That is very unfair.

VC is a long-term business, with the average time from founding to IPO ranging from 8-10 years depending on the year. If you look closer at this list, you'll see companies about to IPO (Amplitude, Relativity Space, Embark Trucks) and several multi-billion dollar exits (e.g Segment <> Twilio, Twitch <> Amazon).

Lastly, the business is all about power law, so these small exits outperform the remaining portfolio by orders of magnitude. I bet they are beyond excited with their returns.

Also consider that YC at the start had few companies per batch. Also a tonne of large acquisitions.

An ipo isn't the only way to exit successfully.

Amplitude and Gitlab will IPO soon, and MessageBird is a highly likely one as well.