It sounds like you aren't really interested in a rational discussion by the second half of your post, but the typical arguments (incl in the post) for are that market makers reduce inefficiencies in the market & provide liquidity that significantly reduces the bar (i.e. make trading cheaper) for retail investors (like you or me) to trade.
I think it is generally accepted that society does benefit from a modern and efficiently run market. Whether or not automated market makers contribute to this could be up for debate, I guess.
I think it is generally accepted that society does benefit from a modern and efficiently run market. Whether or not automated market makers contribute to this could be up for debate, I guess.