Just fount this thread regarding alias folder icons. I to am tremendously disappointed in terms of loss of this feature after updating from Catalina to Sequoia yesterday (yes, i know its a long time, but things like this are exactly why I prefer to stay put when my system & workflow are working). Im a graphic designer & I rely heavily on alias' in my work flow to identify artwork & files I need. This is such a major setback I cannot even begin to express how F'd this is!. I have tried everything listed in this thread along with other ideas & nothing works. Can not even find any 3rd party aps to rectify this. So, my only workaround is a not so elegant solution, but it works & may help others. I make an alias, then copy the ORIGINAL and paste in into the alias with CMD I thus replacing the generic alias icon. Then I add "_a" to the alias folder name so I know its an alias (I used to rely on the little arrow on the lower corner to identify an alias). I can only hope these pasted icons on the alias stand the test of time & don't get wiped out by another OS update.