Him joining the Rams kind of reminds me of the NBA when a bunch of veterans would join the Lakers in hops of a championship. For him it probably gives him his best chance at a superbowl. But I'm just guessing
The 2000 Redskins and, I believe the 2010 Eagles (might be misremembering the year) also tried this and it didn’t work.
However the Bucs succeeded at this last season. Of course, they had Brady. The Rams have a talented QB that has won fewer postseason games than Case Keenum.