@Dave well that's a shame. To be fair, the only time i tried so use it over wifi was on the 2ds, which was pretty slow. It worked only with low resolution, so just a cool experiment, not really practical.
That said yeah if you replace the laptop I'd focus on the best wifi card possible and leave the power to the server. I'm actually planning to switch an old laptop to an orange pi for this reason.
@Dave @deadbeef for the gaming part you don't even need the second pc connected to the tv. I've been trying sunshine and moonlight (a server and client for game streaming) and it's been running really great in the same network. The client can even run on an old nintendo 2ds, so your laptop should do more than fine to try, that way you'd only have a media and a gaming clients on the laptop, everything else to the server in another room.
I'm currently using a similar setup but with Jellyfin instead of kodi, working great for a few months.
@ShortN0te @0x0 I mean the real problem here is that MS office is a mess but somehow still standardized, so "enforcing standards" would be as easy as showing MS the middle finger and using libre office. They'd save a lot of money and time, it's a clear win-win scenario imho