Every online resource is someone else's computer. There's no free lunch.

Don't take valuable resources for granted. Consider paying a subscription or donating a small amount if you can. In the case of Wikipedia, you can also contribute by correcting mistakes or writing technical articles.

Most "free" services are indeed paid by ads, incentivizing people to create addictive crap instead of true value. We end up with bloated platforms in which the gems are buried in a sea of nonsense.

That's also why I'm experimenting with #nostr: zapping gives users the power to decide what is valuable enough to be paid for.