Your comment got downvoted, because on this site it is frowned upon to write lazy, confrontative and uninformative comments. If you don't have an argument that furthers the discussion consider not writing instead.

Simple systems have the advantage that there are less moving parts. Less moving parts means less chance of failure. That is a trade-off an engineer will sometimes take even if it means building a new thing, sometimes something with more moving parts is needed and that is okay as well.

Maybe your requirement is to have a doorbell that does work when the internet is out. Who knows? OP might live in a place where this happens more often. Or they might not and like the idea to never again have to think about their doorbell-manufacturers cloud and the latests exploits targeting that IoT product. There are many reasons why simple can be the right choice and any true engineer would say: "depends" instead of "so what".