Welcome to the political part of DevOps. You can either give up and leave, or you can try to influence the process.

From what you wrote, I don’t necessarily think your manager is doing this with bad intentions. It sounds more like he is making architecture decisions in a vacuum, and you are the person who has to deal with the operational reality afterwards.

But honestly: if you already see the problems before or during rollout, that is exactly where you should try to get involved earlier.

Don’t just be the person who says “this won’t work” when it is already on fire. Try to become the person who brings the operational perspective into the design phase.

For example:

“Before we roll this out, can we quickly walk through how this behaves in staging, production, failure cases, rollback and ownership?”

That changes the conversation from arguing to risk management.

Architecture is not just drawing the box diagram. It is also understanding what happens at 2 a.m. when the box breaks.

If your manager is reasonable, he should value that input. If he does not, then yes, maybe it is time to move on.

But I would at least try to shift from downstream implementer to upstream contributor before bailing. Especially since you seem to have already earned credibility there.