It's nice if it is for some things, but there's a generation, it may be 8th (what you have) where hardware transcoding got a lot better, and that generation or later is considered ideal (at least, among Intel processors) for Plex for hardware transcoding.

My last server was on a 4th gen Xeon. It was good for 1080p, but tended to choke on 4K transcoding. I was always getting "server not powerful enough" errors. (Current server is a Mac mini, M2 Pro. I think it's roughly equivalent to a 12th or 13th gen i5? Apple M-series tend to beat Intel on power per watt (being ARM64 rather than x86-64) but I'm not sure how they play out in a benchmark. Both are more than enough for Plex though. And of course, don't bet against Apple for multimedia stuff (not gaming). Professionals in media/animation tend to prefer Apple machines for a reason. So it follows that they would at least be capable for Plex.