Then why did you pay for it? Buy a Galaxy Tab. They've got similarly-priced high-end models with OLED screens and an App Store model you like.
Not every product has to be designed for your wishes and needs. That's what competition is for.
In contrast, users report the iPad reliably lasting at least 5 years without noticeable slowdowns [2]. There are surprisingly few other Android tablet alternatives aimed to compete with the iPad (especially the iPad Pro).
This makes the iPad the only option for a high-end tablet that lasts years without upgrades. There are also other benefits of the iPad (e.g. better stylus with the Pencil, better variety of apps in the App Store, less buggy apps from the App Store), but these can be considered as reasonable tradeoffs in favour of an Android tablet (no walled garden). However, I personally don't believe that the short lifespan of the Galaxy Tabs make them a reasonable competitor to the iPads.
[0] https://old.reddit.com/r/GalaxyTab/comments/mzwzew/s5e_slow_...
[1] https://old.reddit.com/r/GalaxyTab/comments/od1f4v/galaxy_ta...
[2] https://old.reddit.com/r/ipad/comments/m4013a/how_long_do_ip...
IMHO, the solution is iOS on mobile, Windows on desktop and Linux on the server.
Because you cannot install anything on your iOS/iPadOS device from anywhere else.
I absolutely hate App Store and their stupid policies, I hate that I have an iPad Pro on which I cannot install everything I want because of their idiotic policies, on a device I paid more than 1000 EUR.
I cannot wait till EU will force them to allow competing app stores on iOS/iPadOS