Comment by OutOfHere

Let's say the best open source product has a feature score of 70/100, and the best closed source product has a feature score of 85/100, and this is me being generous with the latter. The issue is that just by being closed source, it immediately loses 20/100, bringing its score to 65/100, which is below the open offering. A closed source product carries substantial risk if the company behind it were to stop maintaining it, which is why the adjustment by -20 applies.

Secondly, as I know, the blocker with approximate neighbor search is often not insertion, but search. And if this search was worth a fortune to me, I'd simply embarrassingly parallelize it on CPUs or on GPUs.