AppCompat, AndroidX, and their other library projects have basically made SDK concerns something you rarely have to think about at this point. Usually the only thing you need to consider are security concerns that newer versions force on you, like updated, new or more finely grained permissions. Everything else pretty much just works. My current teams app supports all the way back to API 23, and has only needed to drop support for older versions a couple times for security reasons.

It all works so well with older versions now that on an evaluation from the mobile teams of the new UI frameworks Jetpack Compose and Swift UI, we decided fully in support of Jetpack Compose because it worked very well out of the box with older versions and was getting tons of updates.

We decided against Swift UI since it was tied to the iOS version, and although most people who can update their phone do, significant numbers of users it seems don't immediately buy new iPhones anymore when they don't get updates anymore. As much as the dev experience would have been improved using the latest Swift UI on latest, the lowest version we support is stuck with one of the terrible first iterations. For something like UI, it just wasn't worth losing so many users.