One of the reasons for this is that the vast majority of the time, mobile LTE data users are behind cgnat for ipv4. You can't block one ip without possibly blocking hundreds of innocent IPs using the same exit point.
As a scraper operator on a mobile data connection all you need is a new useragent and browser fingerprint, there's no easy way for a scraper-blocker-operator to tell that you're not a totally new person.
