OP's comment is accurate because Pixels are not "most Android phones". You also don't know whether or not OP already owns a Pixel, so I'd say it's "weird" to tell them not to complain without knowing whether or not they have already voted with their wallet.
Avoiding Google/FB/Amazon/Microsoft or whatever your megacorp of choice is is becoming increasingly hard, and it absolutely deserves being talked about. As do any other things in which our choices and freedoms continue to be snuffed out, and that point should be able to stand alone, without being weighed against things like "Vote with your wallet" or "But in Y thing we have more freedoms now! Why does X matter?" These conversations are also worth having, but they shouldn't entirely replace the a call for alternative paths.
The poster wasn't just complaining about "most phones" but claiming there was no solution.
It seems perfectly reasonable to point out that there is a solution that works at both the individual and global levels. If you want to control your own android devices, there are several good options and if more people start making those choices then the overall situation will also improve.
If you believe something else is being snuffed out, it would help to mention what it is so people can help you. Because making that statement without context doesn't really stand alone, it's also just noise.
And in the case of vendors who haven't...?
You say that such complaints are just noise to Google because they have already acted on these complaints (ie, Pixel bootloaders are unlocked). On that, I think you and I agree re: pointless complaining.
I'm asking, why not continue to complain in an effort to push vendors with locked bootloaders to unlock them? Specific vendors are irrelevant, I'm just curious if you do/don't think people should complain to them, as well.
My comment is not about specific vendors and their actions. My comment is only about wondering when, in your mind, is a valid time for people to complain; a philosophical question. That's why the question is broad - is it OK for people to complain about vendors who have yet to take action?
Your comment just now suggests that, yes, contrary to your post complaining about complainers, you likely think it's fine to complain to/about vendors who haven't taken action you'd like to see taken.
Edit: Your logic in the last paragraph doesn't follow to me, as I was responding to a specific complaint. So that's another reason I can't really give an answer to the question.
1. Anti-user mechanisms (SafetyNet) annoy users.
2. Even though SafetyNet may not be as annoying as something like UAC, it still has deep reaching effects[1] since now the standards are proprietary and nobody can make an actual good UI alternative to the garbage dog-slow banking app.
The irony is your stale rhetoric only applies the other way: Users who were saved by "risk analysis" and firewall type systems don't know they were saved and don't care.
1. I assume this attestation is checked on the app's server - I assume Google signs their attestation that your device is "good" and this is verifiable by the server of the banking app. Otherwise the in app checks could just be nopped.
If other manufacturers decide to ignore the reference... well, that’s bad, and worthy of criticism, but it's at least good that the reference is open!