I'm involved in the Singapore hackerspace.
I think our main problem was that once we had a comfortable core base of members a few years ago, we stopped recruiting more because some of us were afraid that bad people would join as members and none of us would have good enough reasons to kick them out.
When the pandemic hit, some of our members moved on with their lives — they moved back overseas, got married, bought their own places, etc. That caused our membership revenue to take quite a hit.
We made the mistake of moving during the pandemic because we thought that we could save on rent, but the new place turned out to be highly unpopular among those that didn't speak up (it was bigger and cheaper, but there were more flights of stairs to climb). More people left.
Newcomers tend to have a very transactional view of the space. Some people and groups continue to exploit the space because it's "cheap". A bunch seem to be quite happy to pay their membership dues and leave a mess after they're done, because some of the rooms don't get used very much, and enough time passes in between so we don't really know who we need to give behavioural feedback to. We've had people use the space as a hostel because they "tend to work late at night", and an "open source" group thinking that they could share access credentials among their own members because they paid slightly more than a usual membership subscription for one single month (we don't have a group membership tier).
Not enough people want to take long-term ownership over the space now — many think that a hackerspace director is also the space manager, and the person that's always around to fix things up and clean up messes. Creating a culture where members are ideally empowered to take charge of the environment is difficult.
I guess the overarching problem is that it's hard to get an active community going again without critical mass, and expect a bunch of newcomers to contribute significant amounts of ownership and money towards maintaining the space.