Can't say there aren't others who've used my search terms, but some things I search for are pretty unique. And I do a lot of searching. And search speed is consistently sub-second. There's no trickery seeing years-old results from VERY heavily used chats appear instantly. There's heavy optimization happening for search, and I'm very certain default e2ee would destroy that experience. Unless you can point to 1 e2ee service working at that scale with comparable UX. I won't even touch on the local aspect as the amount of storage needed to just store the data is waaaay beyond anything I'm even interested in owning, much less the compute to make it so accessible.

> Also I can tell for certain that with right index grepping tons of JSONs can be very effective on any modern devices.

But to run local search you need to download the conversations to device first which might require lot of (expensive) traffic.