Your comment is focused on buying a home, but there can be dramatic consequences for home owners, the stakeholders forced into paying both agents.

When a seller has little equity and a poor housing market, exiting a primary mortgage can be financially impossible. A recent survey found a large fraction of the US can't handle a surprise $400 expense. So the follow-on effects of these commissions are not trivial for a large swath of the country.

I also agree that depending on location (looking at you SF metro) there are much bigger factors, e.g. constrained supply, inflating home prices.