If you take the total amount of games that get green-lit/Early Access and then see how many stay there or just release as broken. It is definitely very very few that make it through.
A game like KF2 for example, I know the developer and their integrity is well known so I'll invest in it. The only problem here is that I might have my fill of it before it actually releases and therefore not have the full enjoyment I might have had if I played it when it came out fully featured.