Payment channels are possible on other networks as well. Once again, there is no inherent advantage to Bitcoin here. I know because I worked on one (https://raiden.network/). I also dealt with many of its failure modes:

  - insufficient liquidity on intemediate nodes
  - network partitions
  - uncooperative nodes
  - nodes that were liquidity sinks and forced other participants to bear the costs of deposits
  - insufficient market makers

But more than anything: people do not want to use crypto for payments. It gives them no significant advantage over traditional credit/debit cards, it has no built-in solution for appeals or reversals and it forces them to learn a bunch of stuff to be minimally safe...