how is this solved currently? or if not how you suggest to solve it?
UPDATE
theoretically we could try to use some kind of member based priority.
technically as long as we use something like a blockchain, space per time in the blockchain is limited.
Everything that is limited has an value.
even if we use member based priority, still space in the blockchain would have some value, so members could trade it.
which would lead also to an fee market if we reach the current transaction limit.
so why to restrict what is possible on the protocol level?
or just wait and hope that this would be solved until we have significant transactions?
Technological solutions always have an economic impact.
economical solutions always stimulate or hinder technological solutions
money solutions always have an economic effect, which again has an technological effect
economical solutions and technological solutions have an influence what kind of money is good or even possible to use.
Further, we could see it also that way, that maybe someone want to give some voluntary donation in his transaction to support the network. why hinder him?