Tail emission does not solve the problem of high fees. If you want to have decentralized POW chain you need to have high fees eventually, regardless of having or not tail emission.
In order to have decentralized network:
  1. It must be feasible to run a node by individuals, in order to do that:
  2. Blockspace must be sparse, so blockchain doesn't grow too fast, but:
  3. If blockspace is sparse, the competition for it will drive txs fees up.