There's nothing within the 5G spec itself that commands that every single cell site needs to be a massive MIMO supporting 1000s of users at once. Making a micro cell supporting just a family home is enough, then something a bit higher for small businesses supporting 10-100 users, then the likes of Starbucks can deploy bigger ones and finally the Sports stadiums and Corporate offices gets the really high end stuff.
Companies like Rakuten have already shown it's cheap enough to distribute 4G femtocells for free [1] to your users while increasing your coverage
T-Mobile continues to quietly make available their "CellSpot" femtocell for a US$25 deposit, which is good because it's the only way we would have actual cell service here in a rural part of New Mexico. It is doubly good because whatever server T-Mobile uses for their wifi calling service(s) is the biggest dumpster fire in their entire business.
Non-TMO VOIP and video calling works like a charm. By contrast, TMO Wifi calling can't deal with MMS SMS, drops calls and generally is flaky as shit. The cellspot makes all of that work just fine, and is better than driving 2 miles to get to a reception point.
Again, 4G/5G are not WiFi, they are much more complex and reliable systems and support mobility, even if of course they can now be used in the same way as WiFi ("he who can do more can do less").
Companies like Rakuten have already shown it's cheap enough to distribute 4G femtocells for free [1] to your users while increasing your coverage
[1] - https://network.mobile.rakuten.co.jp/guide/rakuten-casa/conn...