Way back in 2017, when the St. Louis Cardinals signed Brett Cecil to a four-year, $30.5M deal, I think the general consensus was that it was a good bit of money, but that Cecil was a good pitcher and would be able to do almost anything then-manager Mike Matheny asked him to do.
The Cardinals had a gaping hole in their bullpen from the left side and bringing in Cecil filled that. As with most signings though, there were red flags. Signing a 30-year-old reliever to a four-year deal in general carries risk as the player ages. That is normally not a huge barrier, but it is one.