I’m not a writer but to me someone saying they were written into a corner is just an excuse for not being creative enough to get yourself out of the corner you think you’re in.
Look at what Valve did with Half Life. The series ended in 2007 on a big cliffhanger with a major character death. Some would say they wrote themselves into a corner. Instead they said “f*ck it, this is our story and we can do what we want.” So in the new game-
-they used the time travel and inter-dimensional stuff that exists in the Half Life world to change the course of events in the universe so that the major character does not die and now the corner has been removed entirely and the story is open for more games to continue.
Granted it took them 13 years but the point is if you’re creative enough you can think outside the box and come up with a way to resolve any “corner” that you think you’re stuck in.