Some repos like Cromite, Ceno browser does not show any contributors on their main page despite a huge list of even recent contributors found at the insight>contributors graph.

Whereas, I've seen other repos that proudly display their top contributors (Searxng, IronFox etc). Why is this so?
Do the owners toggle off a button that should show off the people contributing to the project

Ceno:
https://github.com/ceno-app/ceno-android/graphs/contributors?all=1

Cromite:
https://github.com/uazo/cromite/graphs/contributors?all=1

Not certain, but that sidebar might be github account contributors, and the commit "contributors" may not have github accounts.

Didn't know one can contribute without an account. I thought it's something 'bout email address

Anyone can commit to a git repo, they don't need a github account. They could be doing their development on a different git host, and mirroring it to github.