* fundamental performance
* practical utilization
I led a prod project that uses FAISS at a bank. A huge amount of the work was about making the index practical in a real IT environment. For example we had to build a sharding system to allow it to scale, but also to allow it to be rebuilt with 0 down time. There were many other significant engineering steps required to get it depolyed.
So, I would say that if Pinecone could solve these problems they don't need to have fundamental breakthrough performance vs the open source systems. On top of that, as every dev knows, there are a bunch of hygiene components and features that prod software wants - connectors, admin interfaces, utilities. $50m is probably a bit low to cover all of these and the marketing to be honest - but it will go a long long way and I guess that there's series B funding to get over the line if they don't sell out.
On the otherhand they must avoid over-committing to the indexing approaches of today because if someone does make an algorithmic step forward and Pinecone don't / can't take advantage then the features that they provide that enable deployment are a matter of engineering. Also, at the end of the day I think vectorDB's are going to be an important niche in the enterprise and not at the scale of data warehouses, lakes, or application DB's. I think that fitting them into the enterprise IT puzzle scape is going to be very important in making them commercially successful and good VC investments.