I was messing around these day trying to install KODI on Rpi1 and doing some stuff with gpio at the same time, and while I was trying out different things it came to my attention that a fresh install of raspbian buster with kodi seemed noticeably faster then a fresh install on LibreELEC.
Now I am not sure if you can really compare, since LibreELEC had samba enabled and perhaps there is some other stuff missing that would make raspbian slower, but I though it was interesting.