The founder and the other two guys that were there in the beginning are still the biggest committers in odoo. It's a striking difference from pg or zuck or other people the same position in US who only have toy projects.
There might be some misunderstanding about what "the biggest" means: they have the largest proportion of commits to their name, percentage-wise, they don't have a majority of the total commits. Ie, the founder has around 1-2% of all commits, when the company has 100~ish full-time devs.
Founder here. I don't develop anymore since a few years with some exceptions (e.g. the ORM refactoring if v13). I still spend 50% of my time to improve the product, but more as a product owner. (The other 50% is to improve the company)