https://www.monerooutreach.org/stories/RPC-Pay.html
I reckon that more public nodes might be needed to meet the demand if we are lucky enough to have more investors, adopters in the next bull market.
The RPC pay system is basically meaningful only for coins with CPU mineable (i.e., ASIC resistant) PoW algorithms. CPU mining in AEON is no longer profitable after the fork, so the RPC pay system makes little sense.
I'm also a bit skeptical about the actual effectiveness of the RPC pay system in general, even for Monero. For someone running a node and offering goods and services with the RPC pay system, he'd need to wait for a long time while continuously serving lots of customers before seeing the actual income (a solo-mined block). The income frequency can be higher for some very large and popular operators (like the top mining pools), but not so much for small businesses.
Also from the customer's point of view, especially in the context of using a remote public node, I think it'll be quite cumbersome to have to top up some credits (by mining) before being able to use the node. Noobs will cry "I don't want to wait!" and there'll be someone willing to offer public nodes without requiring any RPC payment.
We'll see if the RPC payment really proves to be useful or not.