Listing the messaging App here is like comparing apples to oranges, gRPC and FIDL are for different purposes from technical perspective, people must have evaluated leveraging existing tech vs. creating a new one before the investment.

I've been only for 2-3 years ato google, butit felt like (Ads-team perspective) that protobuf is the building block in google. Some databases can hold as data as protobufs, and then convert these row oriented beasts into multi-million column databases with each protobuf leaf being separate column (!) such that analysts/linguists/statisticians and other scientists can lookup their data quickly (given some latency of minutes to hours).

You listed a number of services that are closed or have been merged together to be fair. I'm also not sure what the point of listing sms from a phone service is.

You're missing the chat features of Google Maps, Google Pay, and Google Photos...maybe a few others I'm missing?

Don't forget the built-in chat in google docs that nobody uses! (Yes, the one other than the commenting system).

Oh my goodness, TIL. I know what I'll be doing tomorrow at work...

YouTube had a chat feature at one point recently.

You are not contributing to the discussion. your comment is irrelevant to the subject.