This is all they have to say about this, which is unfortunate, because it dramatically understates just how important religion has been as a community builder and just how much of the loss of the third space is actually just a loss of religion. In 1999 70% of Americans were a member of a formal organized church/synagogue. In 2023 that number was down to 45% [0]. That is an absolutely staggering difference.
Some commenters have noted that it's hard to find a third space in suburbia. This is true if and only if you ignore churches as an option. In your average US suburb or small town you'd have a hard time finding a home that isn't within walking distance of some church or another. These were the third space for most of America for most of history, and they were very accessible.
No matter your opinion on what the future of organized religion should be, it's weird to have a discussion about the disappearance of third spaces in the US while only giving a token nod to our single most significant historical source of community.
[0] https://news.gallup.com/poll/358364/religious-americans.aspx