Back when we were house hunting, we experienced several sales where the house was sold for cash at 10-30k over the asking price before offers were even open. If we do sell, I'm sure as hell only selling to a family (not that I'd advertise as much, I'm sure they would and have made fake families to purchase houses.)
If a house sells before bidding opens, it’s not necessarily the corporations, but yes it’s an unfair advantage to someone. Back when we were looking and the market was even hotter, we actually did get in on that side of the process a couple times.
However that early access was never exclusive and never successful for us. I actually wondered whether it was just a scammy tool for realtors to get feedback on the asking price
And “cash” does not necessarily mean cash. I believe it just means no contingencies on whether or not the buyer can get a mortgage and when. The buyer is already approved for the necessary amount and desperate enough to gamble that nothing will go wrong