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.