A concern I have is about security (hash rate) as a function of block size.
I am assuming that hash rate is correlated with revenue from mining.
Total revenue from fees as a function of block size should be a curve. On one extreme of the curve, if blocks are too big, fee revenue tends towards 0 as there is no competition for block space. At the other extreme, if blocks are too small, fee revenue is limited only to what the most valuable use case(s) can afford. Somewhere in the middle there should be a sweet spot where fee revenue is maximised. It's not a static curve though, it should change as demand for block space changes.
Failing to scale the block size as demand grows might be forfeiting potential miner revenue and hence security.
(I don't think that should be a primary concern though since decentralisation should come first, but I'm just pointing it out as a secondary concern).