Both of these companies need to have their asses handed to them. Not just by the US DOJ, but by every country. What we do with our phones is bigger and more important than two companies that got there first. They'll still have their trillions dollar market caps after the DOJ tells them they must allow web installs.
Apple and Google's only role should be to provide a hermetic sandbox with permissions layer and do occasional malware scans. That's it. Once we buy the devices, they're ours, and these companies should have no say as to what innovation takes place and what customer relationships are built after the initial sales are made.
Ah yes, Google is so draconian that on Samsung devices Samsung Internet is the default browser and Swiftkey is the default keyboard. And all the settings are incredibly easy to find, you can sideload easily, make any app the default for it's category, etc... They are not close to equivalent.
This notably doesn't even achieve it's supposed goal of keep anything secure from anyone - bypasses are found usually days after it's "fixed". That only leaves the conclusion that Google wants to make it painful so as to discourage anyone from stepping out of line. Because that's the only thing it actually achieves, and it does so remarkably well.
I haven't found the need to root mine, there's plenty of flexibility in unrooted Android. I use the browser (actual browser, with its own engine), password manager, search engine, PWAs, email app, launcher of my choice. I use F-Droid for generic apps (like QR code reader).