It's becoming clear that merge trees and compaction need to be addressed next, after delete vectors brought them onstage.
Vertica will actually look up the equality keys in a relevant projection if it exists, and then use the column values in the matching rows to equality-delete from the other projections; it's fairly good at avoiding table scans.
As an industry, we keep forgetting these things and reinventing the wheel because there is more money to be made squeezing enterprises than providing widely available sustainable software for a fair price and than losing mindshare to the next generation of tool and eventually getting sold for parts. It's a sad dynamic
It's true that Vertica sales are optimized for large enterprises -- they just don't have the VC cash to hire 3000 sales people to sell it to the low end, so it doesn't appear on many people's radar.