It's been way too long since our previous 3.5 maintenance release! This new Godot 3.5.3 fixes a number of important issues and adjusts to changing platform requirements.
I've been working on a Godot project since before Godot 4 was out and it's so far along now that it wouldn't be feasible to port it to the new branch. I'm glad that they're still supporting version 3.
Multiple games are already done with 3.x and it's unfeasible to port them to Godot 4. For example the Linux input fixes were flagged by the Cassettes Beasts devs