I experience pains trying to merge PRs

I'm currently at a company, where my immediate manager chooses to merge all PRs by himself.

Thus, I'm at the mercy of "what he feels like" when I need to use something from an earlier PR, that hasn't been merged yet.

I tend to have a cadence of submitting one PR per day, and the next day can use the work that I had from the day before.

Anyways, I asked my manager "Can I merge this PR?" that I was waiting for. He got hostile and said "No".

I then asked can he merge it for me, so I can use that work, and he got hostile again.

I'm just wondering other peoples perception on a company that does this, what to do about it, and any other insight you may have on the topic.

It feels kind of like someone with too much power over something super simple.