What would be the costs for forcing every node on the lightning network to provide watchtower services by default so that the burden is shared by other users maintaining the default and with consideration for relative value across the second-layer and for the rate at which users go offline? Could this work for lightning or other state channel networks? Why, or why not?
So, what if all nodes in state channels are arbiters/watchtowers by default, but the cost of computation to support watchtower service on the network for a node (or node pair/channels) depends on the cost of ‘need’ of that node to have state/in channel transactions backed up, which is relative in value to other nodes in the network and to the rate at which nodes fail in the network. State channel users may choose to not use watchtower services at all, use watch tower services but not support it for others in the network, in which case they pay watchtowers at a premium, or to both support ‘watching’ and establish state channels. Also, if the responsibility of ‘watching’ should have a reasonable level of redundancy over periods of time so as to relieve the burden of computation costs of all watchers... sorry
tl;dr - the first part up to ‘why or why not’^^;