Having worked at both kinds of places, one thing I've observed is as the team size grows, the places with many-hats approach end up/or have problems with accountability. For ex: at the end of the day who's responsible for devops (automating things that can be automated, and making sure the data science team doesn't wait for 3 weeks to get a simple security group access etc..) and things like that.

For sure, there'll be problems other way around too. So there's no one-solution fits all problems.