I've held this view as a senior dev in a small company, a senior dev in a big compant, the co-founder CTO of a startup with 5 devs, and I continue to hold it now I'm an EM with many teams in a really big company. It's not about team size. It's about fixing the right problem in the right place. PRs just aren't that. They're useful if you have a problem with people not meeting a good standard, but they're not useful as a gate for whether or not the code works or if it's been architected in a sensible way. You need to know those things earlier (especially in a startup where speed is paramount.)