"When realtors' business model gets disrupted, sellers will not end up getting the same prices for their houses as they do currently, or get to keep the 6% that now goes to agents"

It's not clear to me that that is true. All economics tells us is that in the current system, sales clear, which means that buyers are fine buying at the current prices and sellers are fine selling at the current prices less commission.

If the commission were to suddenly disappear, it is not clear if the buyer, the seller, or some mix would retain that money. You're suggesting that the buyer would retain all the money without evidence, whereas basic logic would suggest that the seller has more economic power (because housing prices generally appreciate faster than inflation), particularly in hot real estate markets.