... If it keeps rising,btc will no longer be prefered for payments. Is there any solution to keep fee below some level?
Have you considered the possibility that Bitcoin´s best use case is being a store of value due to the propositions
that make it a sound form of money? It may have originally been intended to facilitate payments as well, but the world
needs sound money more than it needs another payment method (paying for your coffee doesn´t need to be broadcasted
to all nodes over the world, a credit card works fine for that).
Less usage due to high transaction fees therefore may actually be a good thing as people realize that they better hoard their Bitcoins
instead of spending them.