While Google tries to address this by centralizing everything to their services app (which is a nice Open Source solution since it can be swapped; we'll see what happens with Huawei), some vendors still want to claim their turf. I thought that has been getting better, but for the past few years I've found it best to buy Google's version of whichever product, and have been very happy with them (perhaps since I've become more conservative, the crazy pace of innovation lives on in the mainstream Android world, with Apple waiting to see what's sticks before they include it).
I don't "blame" people for buying iPhone, it's certainly a safe choice, but even though I'm not that demanding I just find iPhones to be too limiting (that is partially a Raskin vs Englebart thing). Oh yeah, and Google's on-device AI features are actually useful. However, in the long run Apple is developing a vast closed world akin to a monopoly that will create problems (and if I hear that cheesy default ring tone again or see another film/tv person pull out an Apple device which are the minority in use, I'm going to lose it).
Understand re; samsung, but as a consumer I don't want to spend weeks researching compatibility between all of the devices I own/plan on purchasing. Another example; I bought a sony bravia TV which runs android TV. Android tv advertised that it supports dvr recording features. Except sony force you to use another third party app "youvirw" which they ship an outdated version of which doesn't work with androids flavor of live recording.
Unfortunately this is rife across the android world; watches incompatible with payments, stock launchers that are incompatible with android OS features, the list goes on and on. And the issue is that all of these are sold as "android" devices, and it's not until you're knee deep in the ecosystem that you realise that it's all just lipstick on a pig.
Mt experience with the manufacturer-alternative apps is that in some cases their existence stops the alternative from working correctly (samsung knox vs android work profiles, fitbit pay vs google pay, huawei photos vs google photos),which just sucks. And you can only know about these issues if you research the compatibility of every app you want to use with your planned device...
And understand re; cheap devices, the comment thread is deep here!