Mostly AA and indie game titles. The simulator scene is still going strong with dedicated servers (like squad, arma, farming simulator, the hunter etc etc).

Larger titles swapped over to more control in order to extract more money from the players, but also control the experience.

There is however some AAA titles every now and then which support hosting your own servers. But they're quite few these days

Many PC-only games do, more likely to do so the older they are. The newest I'm familiar with is Valheim.

I'm actually looking for Android (Kindle) game recommendations that are cross platform and allow self-hosted servers.

Mostly non-AAA studio games. Then there's plenty of games with steam workshop or nexusmods support, even easier to mod these days as they use Unity or Unreal and you don't have to rely on an homegrown SDK release.

These days? Not many. I’m sure there are some but probably one of the most popular that I’m aware of is Minecraft. There are quite a few custom server implementations alongside the official Java one.

Battlebit, Valheim, Core Keeper, Minecraft, Enshrouded, Palworld, Ark

Given the thread, I'm assuming their mostly referring to CS 1.6, but games like Minecraft are another example.

Factorio and Minecraft.

Rust!