Replacing the entire moderation team of 5000+ subs is not a practical solution and Reddit admins know it
Which is why /u/jailbaitlover I mean /u/spez is sending the message that they would gladly give total power to whatever mod crosses the picket line so they can boot the rest.
If Reddit had to replace all these mods it would be complete chaos and is not much better than the blackout. They will see the same exact problems Twitter has seen since they fired most of their content moderators.
It's volunteer work, which some people enjoy. Much like being a volunteer firefighter or member of a local club. I have modded across Discord, Twitch and also Reddit (for a short amount of time) and there is a certain joy it brings you. You get to care for a forum in which people like you discuss your favorite topics. You get to keep your own community clean and happy. And having that power and responsibility does give one a lot of joy. Think about it like it's parenting. Nobody is gonna pay you for having kids (in fact you're gonna lose a bunch of money), but when they succeed in life it makes you extremely happy.
I used to be a volunteer moderator for a non-reddit site. I did it because I liked the place and wanted to keep the asshattery down to a dull roar so the people who weren't shitposting would stick around.
I did it, albeit a very small community. I cared enough about the topic to give other people dealing with similar things some space to build a community. Mine was luckily mostly dead, since I don't care about building a base or keeping it going, but it served well for its time. Anyone who thinks modding is anything but a labor of love doesn't make for a very good mod.