When you buy a print copy, it also has adverts. The price you're paying is subsidised by the adverts, it doesn't completely cover the costs.
Perhaps there are two possible ends of the spectrum. On one side, you have to pay for all news that you access and there is no advertising. The news will be expensive, so only the wealthy will have access. The government can subsidise it, but that runs the risk of politicising it.
At the other, there is only advertising-supported news. The content you see is decided by whoever bids the highest.
A blended subscriptions plus advertising model tries to find a middle ground. I guess the argument is that advertising would be OK, if it didn't track your every movement and share that information with thousands of scummy companies. Is that even possible now? Would advertisers pay if they didn't get that information?