Let us be able to decide what fabric loader version we want it set to rather then having it set to 1.16.5 no matter what. This can help with incompatiblities with sodium related mods that simply cant be used with 1.21/1.21.1 (probaby effects more versions then that but I've only tested those 2 (Doesn't seem to be a problem with 1.21.4 or 1.21.3) ) Theres no reason not to do this and its rather annoying not to have access to mods like sodium that are essential for using fabric.
Me and many other players would apreciate if you fixed this problem.