Why the Bearcat was not merely a stopgap before jets

Was the Grumman Bearcat only a stopgap until jet fighters arrived?

No; it was one of the mature final forms of piston-engine carrier fighter development.

The Bearcat was more than a stopgap before jets. It belonged to the last generation of highly refined piston-engine naval fighters, much as the Skyraider became an ultimate expression of its own type. Designers also worked before carrier jet operations were proven to be a dependable replacement. The aircraft deserves to be judged as a mature operational solution to contemporary requirements rather than only through hindsight about the jet age.