Yes, nothing special - if someone else has your phone, it's not your phone anymore.
I’d much rather have potential “evidence” against me on my phone, than on my laptop.
The stakes are very high though, and the attackers very motivated and well resourced, and I suspect there’s enough political pressure on them both to do only “a good enough job to make it look like they’re succeeding”. If anybody thinks the NSA isn’t several steps ahead of both Apple/Google and NSO/GreyKey, wtheyre fooling themselves...
Edit: it seems that Signal uses db protection but in a way that fails for a cracked phone like this (?): https://news.ycombinator.com/item?id=26096778