I've done quite a bit of angel investing and have a pretty good IRR. The key is to make sure you stay within your area of competence or within area of competence of those you trust.

Also, the numbers will necessarily look worse for a fund or accelerator like Y Combinator than for an individual angel. Y Combinator has to fund cohorts of companies, right? they can't just say one year, nope, I found nothing I want to invest in this year. But as an individual angel you can.