Probably because this isn't a new take, we've all heard the same theory many times before. Right now transaction fees are in the pennies. If the price goes up, maybe they'll become tens of pennies or even dollars--I don't think that's a deal-breaker. You should also take into account the lightning network. Transaction fees will have to grow in the coming decades, but if most users stay on LN they won't be directly exposed to those fees.
Currently the money required to safeguard the bitcoin network is equal to the cost to electrify a small country like Argentina.
You say users can be shielded from the future transaction fees b/c of Lightning. Ok, well where does the money to safeguard come from if mining blocks produces less and less of it -- and users don't pay fees b/c of Lightning?
LN enables economy of scale. Imagine a future where the majority of txs use lightning (L2), and on-chain (L1) txs are much more rare. One L1 tx may cost 1mBTC. Or if you use L2, a node might charge you and 999 other people 0.001mBTC to route your payments (simplifying here). The amount of money hasn't changed, but it's spread out among more people.