That's how I started, when I upgraded my PC my old PC became a dedicated Plex server running Linux, then the CPU gave up after 8 years (3 years as a 24/7 sever) then bought a PC to run unraid. Its a slippery slope, I started on 16tb of media 6 months ago, I'm now on 24tb...
My way is just a chromecast.
Sadly thats currently the only solution by adding yet another device but for 40/60€ it's not very expensive. I would give it a try