DFA funds have been available only through advisors. They have a pretty good story about using academic research, broad funds aka indexing, how they trade to reduce market impact of fund decisions, and availability of specialized funds to use for tilts. Overall I think it's quite a good company.
I did a couple of experiments, one about $100K and one about $300K, using an FA who agreed to a 50bps fee. The first one was a sort of middle-of-the-road portfolio that produced middle-of-the-road gains. Slightly less than an index fund benchmark that I use. My conclusion was that returns were good enough that this guy and DFA might be a good choice for someone who wanted hands-off management and valued the non-investment aspects of an FA relationship.
My second experiment was a more aggressive portfolio, basically a worldwide small cap and emerging markets tilt vs my other investments. That one did not go so well and produced about a 10% loss.
Both experiments were unfair to the extent I only ran them for a couple of years. Five to ten years would be a better duration. My only defense is that 10 years won't give me much subsequent time to take advantage of what an experiment teaches me.
Based on researching this I think that the advisors that DFA approves are probably above average in quality. Also note that just having access to DFA funds doesn't mean those are the only funds the advisors use. So ... if I felt that I or someone needed the full financial advisor package, not just an investment advisor, I'd probably start by talking to DFA-approved advisors.
All that said, I recall seeing or reading an interview with David Booth, the president, who inkled that they were considering offering some DFA ETFs. A quick search just now says it is happening:
https://us.dimensional.com/about-us/media-center/announcement-11-17-20 So there's a way to examine the DFA secret sauce without paying advisor fees.