The bloat cost creates
1) storage costs
2) bandwidth costs (as this 1gb or 10gb or 100gb must be downloaded and served over and over in the network - for decades)
3) processing costs / power costs (for decades)
4) I/O slowdowns (if the blockchain can't fit anymore in an affordable SSD you'll have to rely on a mechanical disk which is slow)
5) centralization cost as nodes have to drop out, increasing costs to the fewer nodes that remain. It's a vicious cycle where the less you have, the more the costs, plus you now become an easier target for DDOSing (more costs)
As for the problems that we may need to worry, these are what exactly? That txs without a few cents in fees won't go in in the next block? That's all there is to it.
1) storage costs are insignificant. ($300 = 6TB)
2) a legitimate constraint. (I say the market should find a balance.) FYI SegWit increases network tragic for less transactions it has positive effect of reducing the insignificant storage cost at the expense of using more of the valuable bandwidth cost.
3) the processing cost is not a energy cost but a lost opportunity cost, time is money. (SegWit here increases this too)
4) this is such a far off concern it's not worth contemplating, already future storage technologies are coming on line daily and will be commercially available well before we expect the blockchan to hit 1TB.
5) such nonsense, nodes don't drop out because of the cost of storing the blockchanin or the cost of an internet connection, making it cheeper is not going to increase the demand to run a node. The demand to run a node is a result of wanting or needing to use and interact with the blockchain directly, running a node gives you security that your version of events is consistent with the economic world in which you interact, nodes will increase as a function of market capitalization and wealth distribution.
Thinking the scaling issues are about transaction fees of a few cents is asinine, it's about letting bitcoin grow organically. We are all paying $5-10.00 in subsidized transaction fees anyway, we need allow economies of scale to grow to replace those subsidies.
limiting block size to what we have today with no increase in total market cap = fees/tx will need to gravitate to the $5-10 per transaction to keep the security we have today.