What is the best possible captcha at preventing bots?

I am drafting plans for selfhosting a website, but I really don't want any bots, crawlers, indexers, etc. visiting it. So in this instance I'm okay with having an annoying captcha that takes effort to complete, or even stacking multiple captchas. Is there any stand-out recommendations for this? I feel like I could combine both 1) Anubis with a high difficulty threshold and 2) a competent captcha that actually stops bots, but I'm not sure what that might be. I feel like this is important now more than ever considering how I've seen posts on ai subreddits advertising their being able to circumvent casual captchas with agents and proxies, etc.