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