Please tell me what you think.
We need to combine many possible option to increase transaction throughput, whether it's block size increase, signature aggregation, LN or even different cryptography which have smaller signature size (obviously while remain secure).
In terms of scalability, I don't think it is possible to increase the number of transactions in a block by one without increasing the total block size by some constant. In other words, the total time incremented block size will be at best O(1) in relation to the number of users who have at least one on-chain transaction during that time increment.
That's correct. A decentralized blockchain by design,
'scales' extremely badly.
Because instead of just requiring to add a few more servers (traditional 'scaling' method in computing),
every single node / 'server' on the network would need to drastically improve their hardware.
But don't forget to consider hardware and internet growth.