It is clearly a cause of the supply and the demand. Once the supply affects lesser over time and the demand will have reached a global scale, there won't be any milestones. There'll be stabilization. Thus, the drop off of those sub-groups won't be temporary.
The reason being, there is no volume expected in the early stages of Bitcoin. The supply schedule is designed to compensate for being the only revenue for the miners and when it matures, then fees becomes the primary factor. As you've said, since there is a stabilization, we're far less likely to experience sudden drastic drops in hashrate as we go through each halving.
My point about "4 years being a long time" is that it is sufficient to explore capacity increases in every epoch. It is possible to try to increase the capacity (and the block rewards) to cushion, not eliminate the impacts of a block halving.
There will probably be lots of on-chain transaction with or without the development of off-chain solutions that satisfy mainly micro-payments. What are the needs you're talking about?
If there will probably be lots of on-chain transaction, then why would a lack of transactions be a problem? There will be an equilibrium for the miners as well.
The needs are the demand of the users.
Do you agree that we should discuss about this possible scenario as a community and acknowledge our options? Even if it might never be feasible for an attacker to destroy Bitcoin that way, shouldn't we cover the arguments that go against it?
At least, if we're supporters of it.
I do. So far, the consensus mainly maintains that it isn't a threat, economic wise. There is nothing that you can really do. The only solution out of this is to break the 21 million cap and maintain a tail emission system such that you don't get any supply-shock from a sudden drop in the block rewards. That is, if you assume that the fees aren't sufficient to cover this. So we'll have a fixed inflation every year, kind of like Monero.
If not, then there is nothing you can really do without radically changing Bitcoin. Bitcoin has a fixed market cap, and if you change that then you aren't using Bitcoin. It is more of a non-issue and I believe that there are still quite a bit of misconceptions about how fees dominated mining income would play out. My primary argument against these kinds of paranoia is that, the current scheme actually works. If we want to ensure that the Bitcoin network today consumes more of that yesterday, then that is never going to be realistic.