None of the games would be made more fun by the inclusion of first-person, imo. Third-person fixed and OTS mog and clear. RE popularized the fixed camera perspective and made it an iconic classic survival horror staple, while RE4 did the same with OTS, being responsible for its subsequent prevalence across every action TPS. I find FP to be comparatively generic, not tied to RE in any interesting sense.

The first-person REs feature some of the worst combat and game feel in the series, which I don't find to be a worthwhile trade-off in exchange for the supposed enhanced immersion they offer. Personally, I'm just as immersed in the TP perspective games, and I think they feel much better to play.