Well maybe a bot reward system that rewards useful bots which are generating traffic to good content.
So bots themselves compete for reward rather then reward be guaranteed just because they are convenient to spammers and shit accounts. Most of the bots get abused by spammers and crap accounts because without them they and their content have no hope of longevity here. The bots then feed off that, and the cycle snowballs to an embarrassing mess.
There is a clear divide here.
Those who upload or want to upload good content do not like the bots and avoid using them. Those who don't have good content.. literally beg for votes and utilize the crap out of the bots. Wouldn't be hard to write some code that differentiates and learns what is good content and what is garbage.
Thus slowly weeding out the spammers.
Just down voting them isn't enough.
They should be blacklisted.
In my opinion and with what I learned from AI and ML courses, detecting what good content is is not a problem that can be solved. One persons shit post is another persons gem.
Minnowbooster will work in the direction of stopping all votes on content that just exists to get a vote. It won't be easy but we are willing to put in the work.