Re: Easily solved...
Make targetted ads illegal and punishable by jail terms.
Simply choosing to advertise on one TV channel over another, or in one particular newspaper or journal is a form of targeting.
Choosing to sponsor the Henley Regatta as opposed to your local football team targets your brand to a specific subset of people over another.
Regulation of online advertising to limit individual targeting could and should be better but you literally can't prevent advertisers developing strategies to target their ads at specific gender, age or racial groups.
Of course you can sue on discrimination grounds - but after the fact, and only if you can prove it. The BBC copped a lot of flak a few years ago when someone decided they wanted the next Blue Peter presenter to be from NI so only ran audition/casting-call adverts in NI papers and media...