It depends on what you define as unwanted traffic.

Personally I do not have an issue with bots as long as they behave and are not straight up malicious, so I rely on a combination of rate limiting, a fine-tuned OWASP CRS ruleset and an aggressive Fail2ban enforcement (hit 2 triggers and you get a 24 hour ban, 2 bans and you get banned for 30 days).

My sites also make extensive use of static elements and caching.