That depends on location and GitHub pages generally take a while to execute all the javascript for a usable page even after the html is fetched while pages on Codeberg require much less javascript to be usable and are quite usable even without javascript.

Here are my results for what it's worth

  $ time curl -o /dev/null -s -L 'https://codeberg.org'

  real    0m0.907s
  user    0m0.027s
  sys     0m0.009s

  $ time curl -o /dev/null -s -L 'https://github.com/'

  real    0m0.514s
  user    0m0.028s
  sys     0m0.016s

Sure, it depends on your internet connection. But for Codeberg I see a blank page for 3-4 seconds until it shows something. On a big repo like Zig the delay is even worse.

On Github any page loads gradually and you don't see a blank page even initially.