This is key.  If there weren’t bots…Reddit would make its own bots. Reddit dances a fine line of allowing the population to be a certain proportion of bots because they increase real engagement by picking fights with its real users, as well as creating never-ending “content” for people to read and vote on. They only ban bots when real users notice they are bots - which is less and less frequently - even though Reddit has the tools and information to ban them long before that point. Reddit could easy eliminate almost all of them, but that would be expensive and they’d lose real users as a result.