As I wrote before, the memory footprint of the list is probably small (but only the Safari developers know exactly how much memory it consumes). I'd guess that Safari will on average consume *less* memory when using a content blocker, since ad images aren't loaded.Based on what I read on this forum - size of list affects memory and safari tab reloading, that's why devs are working on optimizing the list.
Not sure what you're asking.Then, how is it different from browser extensions?