Companies (most egregiously Apple, but Samsung, Microsoft, and other tech, farming, and medical companies as well) have been actively introducing barriers to self or third-party repairs for decades. Apple serializes their displays on iPhones, so if you were to swap the screen on an iPhone without Apple's authorization or without specific hardware, your iPhone disables specific features on your new screen, even if it's a genuine Apple part. Apple also has incredibly unfair and invasive contracts with their authorized service providers such that they have to provide a slower return window than Apple's own service centers. Furthermore, Apple et al. don't sell every part needed to fix phones, and even when they do sell parts, they are often sold as packages or bundles that make the parts unnecessarily expensive.

To be clear, it's rare for companies to ban third-party repairs outright. However, the vast majority of device makers artificially limit who can buy spare parts and who can fix their devices via software, by tight supply chain control, lawsuits, or getting governments to seize the few parts that could be obtained. This means that most third-party stores can't compete with manufacturers because they can't get genuine parts without becoming "authorized", and by becoming authorized, they can't provide a quality service.