If you are getting a 15/30yr fixed loan that is FNMA/Freddie/FHA in most cases BANKS ARE MORTGAGE BROKERS. It’s a division of the bank just like a credit card division.
Many think that bank have lower rates which may or may not be true. They usually don’t.
Credit unions can do whatever they want and make their own rules if lending their own money for 30 years.
A good broker will get you very competitive pricing. Pricing changes almost every day.
There are some bad brokers out there.
Nobody can tell you that they always have the lowest pricing.
A refi loan is NOT exactly the same as a purchase loan, it should be slightly easier.
‘Direct lenders'(which includes banks) can deceive you and get away with it, It is not possible for brokers to do this.
If you only care about price, you may find an internet lender someplace far away with lower pricing and you can take your chances if you wish.
It usually isn’t that much better.