Well, there is also the KYC phone numbers, the fact that they don't allow alternative clients, and the CIA involvement.

I have also read more than once that just the metadata about conversations is worth more than the actual contents for most use cases, so in that case Signal is already worse than even NIP-17, yes or no? I guess it makes some sense that analysing all the random garbage people say in DMs will be very costly and useless for the most part, while just looking at the overall trends can be much easier and give good insights from a big picture.