Tge flipside of that is that Google and Apple have no viable alternatives. It would take years to build what they have.
It took Huawei about 5 years with Harmony OS to do it but odds if that making it far out side of China is limited.
The other groups are those who use it identically to how they would iOS (and don’t root or sideload), those that use it as computer replacement, and those who just like to tinker. Those last two groups are a tiny, tiny sliver relative to the others.
I know because I’m one of them and something like 70% of my SWE colleagues I’ve known — including Android users — fit that description too. Most have never sideloaded anything and maybe 20% have flashed their phone with an alternative ROM or rooted at some point.
An individual being good with computers or even being capable of programming has little bearing on if they’re also a phone power user.
I have never told anyone what I, ahem, install.
Maybe the sideloader is a power user in comparison to the celebrities, but who is a real power user is those who can to sideload without the sideloading. Power users of your smartphone are: top-management of the vendor, the Government and 0-day scene. Sideloading actor IMO is just a poser to the idea of a power user.
Snoop-phone useds are powerless.