IMO, more roadies need to get over the triathlon stigmas and adopt some of their ways. And some of the randonneur ways.
They sell really aero BTS double bottle mounts that also holds a CO2 cartridge. Specialized makes one that includes two rib cages. You won't eject a bottle with those. Trust me. Also, they hold a Podium bottle really secure and they make an insulated Podium bottle.
Then you can carry 4 bottles on your bike.
It's like $30. I'm sure plenty of folks who blow money on bike stuff can afford that.
Also, roadies can stash snacks in their jersey or go the triathlon route and buy a top tube "bento box".
I often solo 100k+ rides because I need the uninterrupted tempo by not being in a group. Meaning, on my own for all fluids, tools, stops, etc..... I don't depend on needing a convenience store. I take it with me.