Because when done well, physical spaces allow for community to develop and provide an easier access point for new players and a wider variety of games. I don't really care if you do or not but if you've got a good local shop then it's good for you for it to survive for those reasons.
The simple fact worldwide is that spaces in game stores are taken by card and miniature gamers. TTRPG simply does not bring in the money for game stores that those 2 gaming groups do.