The bigger the blockchain, the more unusable and more centralized it becomes.
Baldly unsubstantiated assertion. Actually two of them. I disagree with both.
1) The bigger the blockchain the more transactions it has processed > the more it has been used > the more usable it is.
2) The
smaller bigger the blockchain, the more transactions can be processed in given interval > the less need to deal with off-chain 'solutions' > the less need to deal with centralized off-chain 'solution' providers > the less centralization.
Economic considerations should also be given for developing countries where bandwidth costs are high,
By ensuring that they have no recourse to direct transactions upon the blockchain? Logical inconsistency duly noted.
edit: emphasized