Tracking issues for improving review process

This issue is used to track how we improve review process to make it not the bottleneck anymore.

## Ideas

### Adapt review style

From @Xuanwo

> Many people mentioned that review is the current bottleneck. That’s also my personal feeling. Some suggested we should engage more people to join reviews and encourage contributors to split PRs into smaller chunks to make them easier to review. Those suggestions are absolutely true and valid.
>
> But I also feel we can adapt our review style somehow. Instead of requiring contributors to address all issues, we can encourage them to create follow-ups (note: these don’t need to be finished by the same person). Some of these follow-ups make great first issues that can help more people join the community.

No files, tests, or entry points are identified. Start by reading the issue discussion and the review-process ideas, then look for a maintainer decision on the proposed changes. Done would require an agreed review approach and clearly scoped follow-up issues, rather than an implementation defined by this issue alone.

Written by the indexing model from the issue text.