> The downside is that this is an exceptionally active repo. Hundreds of pull requests are merged each day, so any branch that you’re working on for more than a couple of days faces a large risk of merge conflicts or worse.

This is only true if the branch touches things that other engineers are actively working on. Which shouldn't really happen since each team owns specific folders. If it does happen it means that the branch can be broken down to smaller deployable PRs.

> If there is an issue with a single deploy, it stops the whole company from shipping changes.

Unless the deploy is a giant monolith or the issue occurs in shared library/infra code, this shouldn't prevent shipping changes. If you are deploying microservices, if a single microservice have an issue, you can still deploy the other microservices since they can be deployed independently. (Unless of course the issue is with shared library or infrastructure code then it would affect all microservices that uses those library/code)