you can become a listening node over tor or i2p easily. you dont necessarily have to open a port on your router. it even works for mobile devices. for example i run a node on my phone. if i didn't have storage issue, i would be able to run it as a full node.

lightning is not the only thing that scsles bitcoin payments.

we need every device to have a hybrid node that starts as light client and downloads data on demand but also slowly becomes a full node in the background.

self custodian lightning can't scale alone, but things like ark, might be interesting.

i think there are places where we can optimize the storage in a bitcoin client, which might make things better.

better ux is important too. install the app and it slowly becomes a listening full node.

i think once we have a good client/node like that adopted, we can add for a new network communication protocol that can work alongside with the legacy raw tpc protocol. it can run on http and websockets. which makes browsers nodes easier to implement as well.