[amenod]

My anecdata (at multiple companies) supports their opinion.

What matters is that there is a clear owner who is the voice of final decision. In most cases there is no objectively better way to do something, so having a person who is a tie-breaker is beneficial. Of course, they must be involved in actual coding, doing code reviews of other people's code and similar. And other people must review the owner's and each others code.

But, having an owner is not the same as having a bus factor 1. There should be an owner, but other people should know the project and the codebase enough to step in at any given time, even as (temporary) owners if needed. And this is only possible if they actually work on the project, even if the approach that the team (/owner) decides upon is not what they would pick.