Imo they should be funded by public budgets the way libraries, school buses, roads etc are.

They are, and many low traffic toilets are completely free.

However, in high traffic areas, some arguments they tend to give against this:

• Asking for a small amount of money deters a vandalism because people would only go in there to use the toilet. Not many people would pay to go and trash the place or put some tags in there.
• It's an easy way to get extra money for maintenance
• In case of drug users it could help because some of them might already spend all their money on the drugs themselves thus making the small cost bothersome. (Although strong blue lights are a better deterrent because they hide your veins)

A lot of toilets in Europe in low traffic areas tend to be free. There's also quite some open air urinals in heavy traffic areas that are free but they smell horrible.

There's also some European countries that allow/tolerate public urination but limit it to non-privately owned natural bushes and require you to do it decently. (Not showing any genitals)

If you gotta pee and you don’t have any Euros on you, what else are you supposed to fucking do?? Literally what are your options at that point?

In places where they ask for money you can often plead your case and can enter without paying. Many places also ask for money without actually having somebody present or blocking your entry if you do not. I've seen a lot of little plates with cash just laying there without anybody being present.

what am I supposed to do? tap my phone and pay .5 usd for the privilege of using a clean-ish toilet in the middle of the plaza. not that big of an issue.