HLS you typed a bunch of hot air, and not much else.
There is nothing a mortgage broker can do that you can’t do for your self. I’ve gotten screwed by a mortgage broker on a purchase. On the other two, I found that I could and did do better than what they quoted.
Of course you can’t compare yesterdays rates to todays. Who said that? Of course rates depend on your credit score. Who said they didn’t? You threw a bunch of crap out there to try and make yourself sound “smart”. You failed.
Shop around and you’ll do your self well. Ignore the hot air that insist you use a broker.