Required checks are your actual standards
If you want to know what a team actually requires of its code, don't look at the contributing guide. Look at the branch protection rules. Required status checks are the things that must pass before code ships. Everything else is a suggestion someone wrote down once.
A lot of teams have zero required status checks. They might run linters and tests in CI, but the merge button is green whether those pass or not. That means the real standard is "someone approved it." The tests are decorative.
Promoting an advisory check to a required check is a small configuration change, but it's a meaningful statement. It says: this matters enough that we will not ship code that fails it. Not "we'd prefer you don't" but "you can't." That's a different thing entirely.
The hesitation is usually about friction. What if the check is flaky? What if it blocks someone unfairly? Those are real concerns, but they're arguments for fixing the check, not for leaving it advisory. A flaky required check gets fixed fast because it's blocking people. A flaky advisory check stays flaky forever because nobody cares.
Pick the two or three checks your team would be embarrassed to ship without, and make those required. Leave the rest advisory or remove them. A short list of things you actually enforce beats a long list of things you theoretically expect.