Just based of what I've seen. Bitcoin block size and block space are scarce and the limitations are also very arbitrary. Currently you can do 1 sat/vb, but what happened in 2020 for example is that as soon as the fee market starts for real, it will shoot up to 100 sats/vB .. and we get true price discovery for block space.

What happens when fees go up is that the market adapts, stop doing some transactions, migrate to other technologies like Lightning. This part is very unpredictable. It's like the people 100 years ago that predicted that food and oil would run out in the world... They base their assumptions on current data. We don't know how the market adapt and what scaling tech will exist in 20 years.

Personally I think one thing is for sure,, if Bitcoin is successful and adoption continues,, there will be a fee market enough to cover security. And it will not be like now with empty blocks during a bear market, it will have a steady market price as world trade continues 24/7.