ISPs mostly aren't public utilities, so none of that applies to them. Taxes generally don't go to them. They're no more public utilities or tax funded than a company that would come to your house and cut your grass.
It is true that several times in the last few decades the government has handed ISPs some cash in exchange for doing specific things like expanding service to certain areas. It's more than justified to be mad at them for not holding up their end. That doesn't make them public utilities, though. The government deserves a bunch of blame for that, too, because it's stupid and handed a bunch of private companies a bunch of money with no accountability mechanism. Of course they're gonna take the money and run.
That's why I'm saying stop trusting the government to fix things like this.
I watch plenty of YouTube, so I get the attraction. But at the same time that's basically like saying your favorite ketchup brand has a monopoly on ketchup just because it's your favorite. You have the power to switch ketchup brands, very easily actually, and you also have the power to watch other content on other platforms. I think talking about YouTube like it's a monopoly is actually empowering to Google. They want you to think it's a monopoly.