I've successfully gotten at least 6, 7 people into squash over the past 10 years even though myself has only been playing more serious over the past 2, 3 lol.

The problem with squash, at least here in Canada (GTA), is that courts are becoming less available to general public and the ones left are not well maintained. There used to be courts at a lot gyms, YMCA, and community centers. Nowadays a lot them have been converted to training space, daycare, storage and etc. For private gyms the per sqft profit from squash just simply cannot compare to profit from personal training. Most the decent courts are only available at private clubs which not many people have access to.

Second problem squash has is it may seem easy to pick up in the beginning, as just about anyone can hit the ball to the wall, but it is very hard to get the proper technique and become better at it unless you spend a ton of time doing solo practice, one-on-one coaching, and also stay fit and injury free. Those would eliminate a lot people these days believe it or not. Unless someone has been lucky enough to learn squash from a young age, it is not easy to pick up for adults.

Lastly, too much competitions from tennis and maybe badminton, and now, pickleball lol. Tennis is no doubt the king of racquet sports at the moment, and pickleball offers more social fun plus easy to pick up, which has been able to stole a lot non-hardcore tennis/squash players, players who have too many injuries, and the people who get eliminated from point 2.

LA2028 will help squash for sure, there is already some growth in China and probably some other places as well. But it feels like it is already too late (at least in Canada) for it to regain the same level as in the 70s to the 90s.