This has been ever increasing for years now. Bots, attacks, scrapers, AI, all these things seem to be the majority of traffic on most sites.
I wish I could go back to the days of doing almost anything at all without having to tell a server what a motorbike or traffic light is.
LPT: switch to the audio captcha. Yes, it takes a bit longer than if you did one grid captcha perfectly, but I never have to sit there and wonder if a square really has a crosswalk or not, and I never wind up doing more than one.