I don’t want anyone to get discouraged because of this post. Bottom line is that it is very easy to make a “live USB” of a Linux distro and play around with it. There is zero risk or commitment in doing so. Another great option is to install it on an old computer you have or can easily get. It may or may not “be for you”, but it is very easy to try out.
I’ve got to admit that I’ve never used Plex (I’m a cantankerous open software fanatic), but how do you get your media on there? You’re hosting your own server so presumably you’re downloading the media somehow. Are you doing it manually? If so, you can do the same with Jellyfin. Is it automated with some tool built into Plex?