I hadn't heard of most of this, and it's sort of an avalanche, so I picked out one particular part to check out in a lot of detail and see if it held up.
The controller was stolen IP
Looks to me like they had buttons on the back of the controller in some way which infringed on one of 105 patents that SCUF holds on specific parts of controller design, and they sued Valve a year after Valve had stopped using the design anyway.
I'm not qualified to say whether SCUF actually invented something no one else would have thought of, and then Valve deliberately copied them on it, but I'm skeptical. I lean a little more towards the side of "SCUF patented something somewhat obvious, and then wanted Valve to pay them rent in order to set their buttons up in a sensible fashion."
But at the very least, saying that it's demonstrated that it was "stolen" is, to me, not accurate.
and is still currently fighting the lawsuit
This part is objectively not true, unless there's some glacially slow appeals process I'm not aware of. It looks like the whole thing finished in 2021. Am I wrong?