You can bundle many rule lists inside one extension. It's how 1Blocker works, and I did it myself for my own adblocking extension.
I'm not sure if this is possible in Chrome's proposal though.
Maybe this change will finally get people to prune Easylist which had 30% outdated cosmetic-filter cruft when I last sampled it along with hobby horse websites <0.00001% people would ever visit. Right now it's basically like an append-only legacy CSS file.
And the limit is easily circumvented by having multiple extensions. I've seen Safari extensions that split themselves up to one extension per block list.