there will come a day when ads are simply too intrusive, and ad blocking will go (even more) completely mainstream.That is, if the war on general-purpose computing doesn't eventually make it nearly impossible to perform any form of adblocking...
Currently, the most popular form of adblock is probably a browser extension. Browser vendors are seeing extensions as a possible vector for malware (which is true) and the trend seems to be for enforced signing. This gives them control over what extensions they'll accept, which also gives them the power to prevent adblocking extensions. It isn't happening now but I wouldn't be surprised if it does in the future. On the desktop there are ways around this but they are far more involved than they used to be. The situation on mobile devices is worse.
https://news.ycombinator.com/item?id=7237725
https://news.ycombinator.com/item?id=9061592
Another form is a filtering proxy. Admuncher, AdSubtract, Proxomitron, Proximodo, Privoxy, etc. These were quite popular around the turn of the millenium... The downside is that setting one up to filter SSL correctly is a pain (for the ones that do support it) and now, thanks to Superfish, the general public probably has a fear of all things MITM, user-controlled or otherwise. On a mobile device it's rather difficult to install and manage one, so hosting it remotely is better, but probably most reliable way to block ads there.
A HOSTS file is another way. It works for blocking ad-CDNs quite effectively, but otherwise is very coarse-grained (easily defeated by ads hosted on same domains as non-ads.) Easy to use for desktop; will likely need to be done through DHCP/DNS server for mobile.
As much as I advocate adblocking, I only do it to the ads that are truly giving me a hard time. Tasteful static images and text-only ads don't really bother me at all. It's the annoyingly distracting animated, page-obscuring, misleading, screaming, user-tracking ones that get killed.