I used Kodi for many years (consistently since about 2008 and periodically before then) and stopped last year, largely because the no server, thick client architecture is less useful than it used to be. At this point almost everything I want to play video on has hardware accelerated H264 and H265 decoding, and so almost nothing I play involves transcoding. I ended up moving to Plex, not out of any particular love for Plex, just a basic idea that the value of having a server running exceeded the cost.

With Kodi I was relying on a bodge of extensions to sync watch status across clients, was maintaining libraries on clients separately (I know Kodi supports remote MySQL-managed libraries, but if I was going to run a MySQL server on my storage and run some kind of background process to handle library updating, why not run a server like Plex?)... stuff took forever to sync, performance for library management was not great. Even for browsing, I found Kodi not very performant for large libraries.

Switching away had some other benefits besides library management. Although Plex has more restrictive UI options, the default UI is much more wife/mom/friend approved. My wife had a stint in a hospital and we could watch films synced, together, using Plex (which also handled all the routing/port forwarding/whatever internally) The Sub-Zero plugin for Plex (now discontinued, but still operational) let me fill out subtitles for my content. Plex Media Manager let me integrate a bunch of external stuff into my library including syncing Letterboxd lists into my library. Mobile support is first class (including a somewhat janky download feature that's great for flying)

After switching away I kept an eye on Kodi, and the major thing I noticed is that development cadence is pretty slow at this point compared to Plex. Now, this is because Plex is VC backed and charges money for certain features, and dispositionally that annoys me a little bit. But it also does contribute to wider platform support and faster feature iteration.

A lot about Plex sucks. They piss away tons of time and effort onto VC-friendly features that have nothing to do with what Plex is. They're currently pursuing some nonsense where you use Plex to search for things available on Netflix and watch it there. They also launched their own free, ad supported streaming service which is annoyingly intrusive. They are stubborn about some design stuff that the entire userbase dislikes. They push incredibly awful changes and then act shocked when they get hundreds of comments from paying customers complaining about how bad the changes are -- recently it was a loud and annoying noise playing on startup. They reverted it after a day, but just generally I get the feeling Plex as a team either doesn't know what their audience wants or deliberately ignores it for VC reason. Obviously I'd be happier if it was free and open source.

Personally, I could easily see switching away from Plex to Jellyfin or Enby, but I can't imagine switching back to a serverless media setup.