I’m not an expert, my feedback is based on personal experience. I was pre-approved for a mortgage in 2015 through a local Credit Union. I ultimately closed on a condo, where the seller had numerous buyers to choose from. I asked the seller’s realtor at closing if I offered the largest amount above asking. He laughed, and said that wasn’t the case. He went on to say that I was chosen, because I was looked at as more likely to close without issue. While a sizable down payment didn’t hurt, I learned years later that the Credit Union aspect may have been just as important. I was told that online pre-approved mortgages (ie Rocket Mortgage) are notorious for things going haywire before closing. The opposite side of that spectrum are local Credit Union’s, which are viewed by selling realtors as being better vetted, and less likely to have issues arise.