What I like most about mpv is how you can control it through its socket. Often times I will play a movie or tv show on a separate monitor, so being able to pause or rewind or change volume without switching workspaces is important. I have in my i3 config, keybindings so I can easily control mpv with my keyboard: https://github.com/ediw8311xht/dotfiles/blob/6a765910ab5ac17...
Additionally, mpv has a powerful script system. One of my favorite scripts is fast foward through intro, which is crucial for watching a tv show. https://github.com/rui-ddc/skip-intro. Another nice script is https://github.com/familyfriendlymikey/mpv-cut, which enables creating clips in mpv. There are a ton of other useful scripts, and its not difficult to create a custom script yourself using lua.
Mpv automatically resuming is also nice for watching tv shows or movies. Only problem is that if you shutdown mpv through killing the window then automatically resuming from history gets messed up.