Hi @Lanedot thanks for taking out time to read through my contribution. You have made very wonderful points that I agree with.
However, I have a slight objection to the idea of sandwich attacks not being profitable on the basis of gas fees being expensive.
Let’s consider @PatrickZuest’s Bachelor thesis on analyzing and preventing sandwich attacks in Ethereum. He even made a summary of that paper here on the forum incase you want something shorter and concise.
Image source : Patrick Zuest
From the image he shared, you can see that in 10 months, the attackers made a consistent profit even though some individual transactions were unprofitable. The research also suggests that at some points, the attackers collaborated with miners which yielded maximum profit. Note that gas fees have been subtracted from the results on the graph.
So some factors will actually encourage more profit on sandwich attacks.