Switching to a more common user agent recently helped only a little bit. At least that is what I believe, unfortunately I haven't done any measurements. It might well be that it helped not at all.
The irony is also that I'm permanently signed in to more services on this computer than on any other one in my household and that it is the only computer where cookies don't get purged regularly.
Also, I never used the RasPi for any automated tasks or anything else that could be interpreted as bot traffic.
The worst offender is Yandex, which is pretty much unusable because it let's me solve the captcha every few mouse clicks.
Any ideas how make a RasPi useable as a work computer?