Introducing a Captcha on a form on my website basically blocked bots 100% of the time. It's arguably good enough from a practical standpoint.
If someone really wants to exploit my site, then they will find a way. You can only make it harder but never truly impossible if you don't want to dispose of all convenience.
Ohne das jetzt genauer nachgeforscht zu haben, könnte man das seitens Lemmy richten