That isn't true. States levy taxes and buyers brokers are a thing in some states, and in some cases they're less fully paid by seller (less than the customary 2.5-3, leaving buyer to provide 1 or 1.5). Closing costs include mortgage costs, too.

I've only ever heard of that stuff paid by seller if seller was a sponsor, and the market was a down market. Think new build in 2020 or in a depressed housing market today.