It also acts as a filter to keep threat actors and spammers out. Open sign ups are actually a bad thing for the overall health of the network. Yes it also keeps out the lowest common denominator normies but those aren’t exactly the ones who contribute to the network as a whole anyway

This isn’t capitalism, there isn’t a need for growth for growth’s sake. There does need to be a more simplified way to onboard users but not at the cost of the health of the network.