Our changes land in main at my workplace, once they've received a code review and all CI checks pass (which includes tests, E2E tests, etc). We use feature flags rather than feature branches, so all diffs / pull requests are against main. We use continuous deployment which means changes are automatically deployed once landed. Changes roll out just to employees, then to servers used by a small percentage of users (2% I think), then everywhere. All risky changes are gated by feature flags so they can be enabled or disabled without a code push.