The U.S. Department of Justice's (DOJ) lawsuit against Apple is arguably the largest technology antitrust case since its battle with Microsoft earlier this century. Regulators are effectively challenging Apple's core business model, and the company may have to remake parts of its tightly integrated ecosystem.

How much difference will this really make? Depending on how this lawsuit is resolved, it could have a major impact on how you use your iPhone, but it may not be as big a deal as you imagine.

Most of the DOJ's lawsuit revolves around Apple's control over third-party iPhone apps. Outside the European Union, downloading software through Apple's official App Store is restricted because authorities have relaxed that policy for Apple through the Digital Markets Act. In addition, Apple places restrictions on what third-party apps can do on the iPhone. Among other programs, all-in-one "super apps," certain digital wallets, and third-party SMS email apps are not allowed.

The DOJ claims that Apple is suppressing developers by reducing the quality of apps that could compete with Apple's own apps, especially those that could help iPhone users switch to Android or become less dependent on Apple devices.

If successful, the DOJ could ask Apple to allow a third-party app store like the one on Android (and soon on iPhone in the EU). That way, they would have a wider choice of apps, especially titles that Apple would not allow.

Wherever the apps are obtained, their functionality could be improved. It could perform more tasks in the background, bundle a collection of mini-apps, or provide SMS messages on top of online-only chat services. It may also make it easier to switch to Android as a result of not having to rely so heavily on Apple's software.

"Apple will be forced to open up its ecosystem," says Hanish Bhatia, associate director of Counterpoint Technology Market Research. This means more interoperability between the different ecosystems of payments, apps, messaging, and devices."

However, we don't expect a complete overhaul of the iPhone app market. In some respects, it may not change at all; Avi Greengart, founder and lead analyst at Techsponential, notes that this is not the first time Apple has faced legal challenges to its app distribution policies. Some of these issues have already been challenged with Epic," he says, "and Apple won that case. Apple may have to make limited concessions, such as allowing in-app purchases from other providers.

Don't expect Apple to rush to open up its platform, even if it requires significant legal changes; the EU requires developers of third-party marketplaces to be approved and notarize their apps for privacy, security, and integrity screening. It also requires creators in the region to demand deeper access to the iPhone's hardware and software features, and only large developers (those with at least 1 million installations) can distribute their apps via the Web. While there are more options, they are not as flexible as other platforms.

The Apple Watch is widely considered the best smartwatch for the iPhone, not only because of its unique features, but also because third-party watches do not work well. Notification response, cellular access, and battery-saving features are all limited by competing wearables.

As the DOJ notes, the Apple watch does not support Android. If Apple's wristwear must be replaced at the same time, it is less likely to switch to a competitor's phone.

If the lawsuit is successful, Apple may require other smartwatch designers to expand access to iPhone features. This would not only provide more features on the iPhone, but also allow people to buy third-party models that can be used in the same way when they buy an Android phone. This could result in more variety and spur competition.

However, this does not necessarily lead to Apple Watch support on Android. The DOJ claims in its lawsuit that Apple uses smartwatches to maintain the loyalty of iPhone users, but it has yet to demand compatibility with Google-powered phones. Like it or not, if you lose interest in the iPhone, you may have to ditch your Apple watch.

The DOJ wants to improve third-party iOS apps overall, but has singled out issues with messaging and wallet apps.

Only Apple's own Messages app can provide both Internet-based and SMS messaging on the iPhone; without Android's iMessage, you risk missing conversations when you leave your iPhone. Also lost would be media quality and useful features such as encryption and typing indicators.

Antitrust lawsuits could remedy the situation by allowing third-party apps with extensive SMS and iMessage support. You will no longer have to switch between Apple Messages and your preferred chat app to keep in touch with friends, and if iMessage supports the Android OS, you can also keep in touch from Android.

Third-party digital wallet apps, on the other hand, do not support tap-to-pay on non-EU iPhones. For that convenience, one must use Apple Wallet. The DOJ may push Apple to enable this feature so that cards, IDs, and other data can be migrated to Android while being taken out of the country.

Whether such a change will happen is another story. Apple recently promised to support RCS on the iPhone in late 2024, making most of the iMessage feature set (such as higher quality media and typing indicators) a true cross-platform standard. However, Apple has not promised to expand iMessage or SMS support. However, given that Apple has already opened up this functionality to third-party apps in Europe, tap-to-pay is likely.

However, there is one major caveat to these potential improvements. It assumes that the DOJ will prevail. According to Greengart, there are no "clear" cases of Apple monopolizing, or even hurting its users in a way that violates antitrust laws. For example, Apple has more than a 70% share of the U.S. "performance smartphone" market, but its share of the overall market has shrunk to about 65%, the official claims. Bhatia adds that proving such cases is "very complicated."

Apple certainly has no intention of cooperating. The company says it intends to fight the antitrust claims, saying they are "wrong in fact and in law." Greengart adds that such battles with regulators take a long time, and even if consumer redress is achieved, "it's a long road to redress."

However, there could be a ripple effect on the industry. Bhatia believes that the DOJ's lawsuit against Apple will be "closely watched by major tech companies. This could affect other apps and devices you use, not just the ones on your iPhone.