Forgive me for being a bit daft, but: What do all of these messenger clients and things bring to the table that didn't already exist on AOL instant messenger 2

Forgive me for being a bit daft, but: What do all of these messenger clients and things bring to the table that didn't already exist on AOL instant messenger 20 years ago? Slack seems like (badly) redone IRC. My computer 20 years ago could run mIRC without issue, and yet my brand new modern macbook pro with 16 gigs of ram chokes on the slack client. WHY? Hangouts seems like (badly) redone AIM. For some unbelievable reason, since about 6 years ago, I can't quite ever figure out how to open or close the "hangouts" application, and google just keeps making it more confusing. It started out pretty sane: either use the mobile site in gmail.com, or open the (beautiful, fast, stable) google talk desktop application. Eventually the desktop application got deprecated, and I HAD to use chrome, but that was essentially okay since it had some nice features. It would dock messages to the bottom of your browser, which was cool. But at some point, google deprecated that, and won't even let you run the old version of it anymore. Now you HAVE to either use gmail.com, or some application that can only seemingly run if chrome (a giant memory hog) is also running. Oh and for some reason the mobile version of the application wants to send SMS messages? But like sometimes it's SMS but sometimes it isn't, an it's not really obvious which is which??!? All of this messaging stuff is seriously driving me crazy. In what world does it make sense that facebook messenger is somehow the easiest, most stable messaging client? WTF? If we could all just agree to start using AIM again, and if they could get file transfers and voice chat working 100%...my god. It would be amazing. And imagine how fast it would run on modern hardware!