I just fired it up, couldn't find anything related to soft body or deformers, neither does there seem to be anything regarding common issues around 2d platformer features character mover is sort of moving in that direction does seem to provide better controls over how I would setup slide/jump and stuff, but still seems like not a great choice for a 2d game that I would like to build.
The biggest issue with overly generalized 2d physics systems is ideally they should be built as patch works and provide escape hatches as the default, since in most 2d games you don't want real world physics.
Angry birds and early 2010 games were an exception when real world esque physics was the well interesting thing. Example Angry Birds, and Cut The Rope.
The above blog even seems to suggest that soft constraints were added recently which is well surprising.
I just feel like Box2D is very lacking albeit less now.
Let me give you an example imagine you want box2d to allow applying weird forces to player most of the time, but you also don't want to allow the player to clip through at certain movements and speeds to avoid weird cases where your character hits a wall and loses all momentum because that's how the physics should work, or it forces some rotational momentum which you have disabled...
Again in a lot of these character controllers you always end up with custom physics setups either way, and this is where I feel like box2d was especially lacking they seem to have worked on it with character mover, but it seems just very late.
Again I have used a lot of it in the past for making shitty flash style games, and it has been great but I honestly don't think there is a great use for it as it stands today in the projects I like to work on.
Ofc it's also largely because I find writing my own physics engine to be easier than picking up a library, and I would probably copy some of the code verbatim if needed for collision optimizations and stuff, but Box2D just feels a tad behind the times.
Again I am not a big time dev, and I am certain since Godot ships Box2D there must be a lot of users of it, but I just don't care enough at this point.