This is such a cynical take. Contrary to popular belief, the vast majority of moderators do care about their subreddits or else they wouldn't be volunteering their free time. The allure of the power to remove some random person's post on the Internet, or to ban them just so they return with another account, pales in comparison to the thrill of watching your community grow and people having fun because of it. And it's not this weird selfish, hey-look-at-me-I'm-so-successful kind of thrill, it's like you joined this thing because you are interested it and now all these other people who are also interested in it are there talking about it. That's what's cool, you set off to make this place where people can talk about this thing that you think is cool and you get to watch it grow and be successful over time. Some of these communities have been around for over a decade, so, people have invested time and effort into them for over a decade.
Moving to elsewhere isn't really as easy as people make it out to be. At the moment "moving communities" means fracturing your community as there is no unified approach to doing this.
The operative word being "unified" which is next to impossible to achieve. If you get all mods to agree you will have a hard time reaching all your users. This in itself presents the biggest roadblock, ideally you'd close up shop and redirect users to the new platform. Reddit will most certainly not allow this, their approach to protesting subreddits that were not even aiming to migrate made that abundantly clear.
So this means that, at the very least, you are looking at splitting your community over platforms. This is far from a unified approach.
This isn't even touching on the lack of viable long term platforms out there. I'd love for people to move to Lemmy. But realistically speaking Lemmy is very immature, instance owners are confronted with new bugs every day, not to mention the costs of hosting an instance. That also ignores the piss poor state the moderation tooling is in on Lemmy. The same is true for many of the possible other "alternatives".
All the new attention these platforms have gotten also means they are getting much more attention from developers. So things might change in the future for the better, in fact I am counting on it. But that isn't the current state of the fediverse. Currently most of the fediverse, specifically Lemmy is still very much in a late Alpha maybe early Beta state as far as software stability and feature completeness goes.
And, yes, the situation on reddit is degrading and this latest round of things has accelerated something that has been going on for a while. But at the same time Reddit is the platform that has been around for a decade and where the currenty community is. Picking that up and moving elsewhere is difficult and sometimes next to impossible. I mean we haven't even talked about discoverability of communities for regular users.
Lemmy (or any fediverse platform) isn't exactly straightforward to figure out and start participating in. If you can even find the community you are looking for. Reddit also hosts a lot of support communities, who benefit from reddit generally speaking having a low barrier of entry. Many of those wouldn't be able to be as accessible for the groups they are targeting on other platforms.