The physics engine mentioned towards the end, Jolt Physics [0] is used in the frankly blockbuster games Horizon: Forbidden West and Death Stranding 2 and yet opens its description with
> Why create yet another physics engine? Firstly, it has been a personal learning project.
which is really rather wonderful and inspiring to see.
Its use in those games is no mere coincidence though, the creator of that physics engine, Jorrit Rouwé, has worked at Guerilla Games since the Killzone days.
https://jrouwe.nl/games.php
It has also become the default physics engine in Godot.
Also increasingly well integrated into Godot.