Do you invest in those using a self directed IRA? And is the 10% coming from interest income rather than NAV appreciation?
I've been looking into several private REITs in the past, and their return is indeed in the 10% ballpark (usually 10% is the ceiling), mostly distributed as interest income. The problem with that is that if you don't hold them in a tax sheltered account, your 10% will easily become 5% after taxes, since interest income is taxed at your marginal rate, so if you're at the peak of your earning career in a coastal city, 50%+ marginal tax rate is not at all uncommon.
In comparison, broad cap index funds are much much more tax efficient via qualified dividends and long term capital gains, so to get 5% after tax from those you need much less than 10% returns.
I decided to give up on investing in private REITs, I don't like the idea of taking a substantial amount of risk just to then send all the premium to Uncle Sam, and being a traditional W2 employee, access to self directed IRA is not worth the trouble.
Many people (not saying it's you) like to boast about their pre-tax return: the only thing that counts is how much you're keeping after taxes.