Real BOTs are more and more using whatwg cartel web engines, namely this has an end. If not all, namely the end was already reached. The ones not using them are more likely to be shadowpaid hackers by the whatwg cartel to ruin anything noscript/basic HTML (or they could be beyond idiotic hackers, unlikely).

Not to mention, many "maths challenges" out there are nothing more than a 'wait loop' in the end. Namely, you could replace them with a HTTP hard refresh timer with human scale wait times in order to get the same pertinent result. Those are actually even worse because they are pleasing the whatwg cartel since those are made to work only in their web engines.

The least they could do is to standardize those 'maths challenges' and make them HTTP header friendly.