As we all know, as reasonable as it is for site to want to make money, there are significant problems with the way ads are currently used on almost every site. Including not just a reduction in website function, but significant risks of virus' and malware. This prompts people to utilizes ad blockers. The response of sites has been not to fix the problems with ads, but to start detecting ad blocker usage and attempting to block access to the site to people that don't want to compromise their safety. This has also extended to the Google-owned Chrome removing the ability to meaningfully block ads.
It would be wonderful if Mozilla took a stand in the opposite direction and took steps to prevent sites from detecting when people are using ad blocking extensions. How effectively this could be done by a browser does depend on the method sites are using to do this, but if there are things that can be done, it would be a bone for Firefox and it's users.