I don't like how companies behave like that and basically push users to upgrade their phones

Garmin in particular makes it mandatory to use their app for SOME connected functionalities (while others work just fine on wifi or wifi tethering). They unsupported old version of android for the garmin connect app pretty fast (my mom's phone was incompatible within 4 years of its release) while they don't support you to connect older devices on newer phones and say they know it doesn't work.

As a user, I don't care whose fault it is.

I ditched both Google in favour of degooglized android on older Xiaomi and Pixel phones that support custom ROMs, and Garmin for any sport equipment.

My next phone will be a Fairphone if they make something with a smaller screen.

I don't know which app you're doing, but I would most likely permanently just not download it or find an open source alternative if it stopped working for me, as no app is essential. Pay attention to the user-base, in particular is your app is supposed to work with a web of users.

While i always try to look for open source utility apps (i use several), our userbase simply don't care.

Context: Our apps are means to connect to our devices via BLE, are free and without ads (fuck ads, fuck all ads), no integrity checks. We don't publish the API but we know of a couple of clients that reverse engineered the protocol and made their own. Good for them. (one of them also came by the office to bring a friend and showed us his app that glued together the functionality of several modules from also our competitors. Cool!)

But given what we do our customers are complete normies, doing what google asks us is the path of least resistance, and gets us most audience.

Those who don't want to use the play store can find the APK in the usual sites, don't care.

If i made app for myself i would indeed distribute it differently.