Node providers are essentially teams that offer access to Nodes without having to run your own node. So instead of sending your requests to a local node, you can send them over the internet to a provider offering an identical API that is running fully-synced, up-to-date nodes available 24/7.
Which is essentially the problem you're having in the first place. There's no reason to pay for a service that offers access to the blockchain, because firstly, that's available free, already, and second, you don't get the benefits of running one yourself. Benefit such as privacy, verifiability and ultimately, self-sovereignty.