1. Preventing SPAM (spammy comments, articles, votes etc.)
2. Preventing email collection (obfuscating could be an option: https://freetools.dev/email-encoder)
3. Clean up server logs (bots creates a lot of lines in server log files)
4. Clean up your Analytics (lot of bots may count as real visitors)
5. Security concerns (not only banks have important data)
6. Avoid automatic registrations (your users list counts too)
It's always a downhill battle, but the people who implement it know this. They don't care if you've found a new workaround, they've probably got 2 more mitigations ready for the moment you think you've pulled one over on them. The ultimate goal is to tire you out as a developer and make you give up. Judging by the amount of frustration I see online, it sounds like "they" are winning.