I've been using IceCat recently as part of a video project I'm doing. I started using Guix just for fun and IceCat happens to be the version of Firefox they have available by default. It has some quirks but it's overall pretty usable and strips Mozilla branding.

It's a shame because I pay for Mozilla features, including Mozilla VPN. But I find this behavior (1) kind of gross, and (2) a clear signal of either desperation or indifference to their mission.