This is something I have thought a whole lot about. I blog and I want that information freely available, but I also need an income. I don't have a problem with the fact that people on HN actively find ways around paywalls which I think people on HN tend to find surprising because I spend so much time criticizing the idea that "You people want good writing and you want it all for free, so you basically expect writers to be slave labor for you."
What I'm saying is that this is not an easy problem to solve because in any business, some of the things you provide will be provided for free. For example, businesses that serve food have bathrooms available for free.
In busy downtown areas or areas with a lot of homelessness, you will see local establishments with signs saying the bathroom is for customers only and some even have security codes so you can't just walk in off the street and head to the bathroom. But they don't charge for use of the bathroom.
If you are a small shop, figuring out what to do for free and what to do for pay is a thorny issue because time is money and it's easy to end up in a situation where you are de facto slave labor.
For some businesses on the internet, your members who are there because it is free can be part of the value you are bringing to the table and if you try to charge and you drive those people away, you may kill the business because now your paying customers have no reason to pay you. The membership base was part of your value position and you've just thrown the baby out with the bath water.
So before you go acting like businesses who give stuff away for free are somehow nefarious actors, stop and realize that successful businesses have to pursue models that are viable and those models have real world factors. This is not just something decision makers at companies can arbitrarily decide willy nilly. You need to be taking the landscape of your marketplace into account when trying to figure out what piece of your product is the piece you charge for or monetize and what piece is something you give away for free.
Historically, TV was free to viewers. You just needed to own a TV, but subscription channels came later. It got monetized with advertising and having a large audience helped you monetize it. That large audience was valuable to your advertisers, so giving it away for free to viewers was part of how you made your money.
So this model wasn't born with the internet. It existed before the internet. And there are valid arguments to be made concerning things like "If you aren't paying for it, you are the product, not the customer" and lots of different angles to look at such questions.
But at the end of the day, there is no free lunch. You somehow need to pay the bills. And sometimes the method that actually works effectively isn't as straight forward as "Well, just charge people for using the darn thing." Sometimes that doesn't work at all and in other cases it may work, but will limit your growth. Sometimes giving part of it away for free is how you grow to the point of being able to make serious money.