That's fair enough, but honestly? I hate that part of GrapheneOS. Every single time I update, I have to reserve some bit of "headspace" for the chance something breaks. Especially when doing automated jobs (back to the F-Droid case), these kinds of problems are quite sensitive. Now I already agreed that using Debian LTS is not a good option, but bleeding edge in such an environment, all for that 0.000000000000000000000000001% chance that someone would abuse a vulnerability in the 48 hours a package wouldn't yet be updated... then I'd say there's a decent balance to find there.
Debian takes years to ship many security patches, not 48 hours, and Debian LTS doesn't have official security support. You're operating under the incorrect belief that most security vulnerabilities get CVE assignments particularly in the kinds of projects that it's built from or that or that they actually ship those quickly. It doesn't work that way for Debian stable and certainly not LTS.
I reckon this is also where "bad blood" comes into play. I mean, the fact that "exerting public pressure" like you said is expressed in terms ranging from "Can't even get their regex right" all the way to "bulls**t behavior" and other expletives, together with the entitlement (not yours, but of others) I've read seems to make this hostile instead of constructive. That's just sad, because you're basically on the same side, while having arguments over bikeshedding.
F-Droid has an egregiously poor approach to security and has consistently engaged in cover ups, attacks on security researchers and attempts at discrediting them with fabricated stories and harassment. They're genuinely untrustworthy people who shouldn't have a highly trusted position. F-Droid doesn't simply have regular slip ups and vulnerabilities but rather an insecure architecture and approach from top to bottom where security is not and has never been prioritized. Not only that, but they do not acknowledge most of the issues and do not take serious steps to address to huge problems with the architecture. Papering over symptoms of the huge architectural issues one by one rather than designing for security is not taking it seriously. There are very few people looking into it so you can't expect to see a steady stream of vulnerability reports and it does not mean they aren't there.
Here's an example of the people involved engaging in harassment, then covering it up and subsequently fabricating stories about it they posted across many platforms:
Why would anyone trust their cover ups of security flaws and potentially breaches in their blog posts? Why do you expect they'd admit to it and tell anyone when they've been repeatedly caught in situations like that blatantly lying about security and engaging in incredibly underhanded and dishonest attacks on security researchers in an attempt to discredit them?