I feel like I want to just stop accommodating my friend's finances
Why don't you want to accommodate their finances?
Because they are spending too much money for things they don't need.
Well, they're not your kid or anything so I think that's fine.  People shouldn't be expected to support others financially unconditionally.  Hopefully your friend manages to reign in their spending habits!
I'll tell them how they should live their life so that others do not have to give them any money all the time.
You can tell them anything you want at this point if you have the time. They probably actually owe you money back, but if you are okay without asking for it then just walk away. No need to tell them what to do, it is not your job to do that either if you don't have to.