In order for Bitcoin to succeed, blocks must be full.
If blocks are never full, then there is never a reason for a transaction to pay more 1 satoshi in fees. As the subsidy is reduced, fees become more important. So at some point, full blocks will be necessary in order to ensure that the revenue is high enough to discourage a 51% attack.
Changes that attempt to prevent full blocks would directly impact the security of Bitcoin.
Can't we have flexible block size? For example, each block confirming 4% of total transactions (numbers are only for example). There will always be some unconfirmed transactions left because block only takes percentage. If 100K transactions are unconfirmed at the moment, 4K will get confirmed in next block, if the demand rises significantly and we have 300K unconfirmed transactions, then 12K will get confirmed in next block. By doing this, the less total transactions we have, the less transactions will be picked up which won't let transaction fees to fall down but at the same time, if demand significantly rises, it won't let big transaction volume to clog the mempool.
Blocks can be always full if block size is flexible and changes for each new block discovery, according to the volume that 3% of transactions create at moment. I don't know how technically possible is that but I don't think that sounds dumb in theory.
Overall, I don't see anything wrong with if we increase current block size. Time changes, technology improves, demand increases. It's not expensive to run node today even if we double or triple block size and the demand isn't similar to the demand of 2010's. You can't have 2010's block size in 2017 and 2017's block size in 2023.
You guys here underestimate how bad high transaction fees are for bitcoin adoption. Rich guys can pay high fees but poor or middle-class guys can't pay high fees. That's why they move on altcoins.