The center of it for me are several communal housing places with large communal areas. They're not true replacements, as the people that live there are mostly similar - young professionals-ish without kids - and it isn't especially open to the public, which makes it not an true third place in my mind.
Businesses can't do it because they have a necessary profit motive - the bar doesn't especially care if you're buying drinks but they do care that they can't make rent and pay their bartenders and other staff.
We don't (or maybe we do) want to just hope a benevolent billionaire or collection of millionaires are going to swoop in and fund their places into existence. They're spending their money on palatial estates where you have to be in the know them to be invited, which makes it not a third place either.
No, third places need to be supported by the government - which churches and their tax breaks, and libraries with their funding, are. We have to accept a larger role of government than necessary evil, however, so I don't know if that's possible.
The problem with that is Americans aren't well socialized, so third places inevitably get the cops called and the places shut down. We all saw the Black neighbors getting the cops called on them by the scared White neighbors for the crime of having a BBQ and listening to music. The legal regime we live under is a huge part of it. Bars were barely a passable third space but when people don't drink anymore, there are no lounges to meet up and smoke pot in and just hang out at for hours.
