I find that difficult. Aside from code reviews, often times your job as a maintainer is:

• getting a refactor or code cleanup in while everyone’s asleep
• shuffling commits around between branches
• fixing the CI toolchain
• rolling back or repairing a broken change
• unfucking the repo
• fixing a security vulnerability

A required review slows all of these tasks to a crawl. I do agree that the kernel is important enough that it might be worth the trade-off.
But at the same, I do not feel like I could do my (non-kernel) maintainer job without direct commit access…