And yes the LN white paper says there needs to be block size increases and yes core devs say they will consider a block size increase in the future when it is needed and safe. But it was needed last year when fees got insane.
There was no block size increase needed last year.
The solution already was there, but noone made use of it. Segwit.
Big exchanges didn't use segwit, didn't batch transactions and a quite heavy spam attack was going on. This all led to a heavy increase in the average fee (to get your tx into the next block).
In the end you choose which fee you want to pay.
And it is safe to do you just have to put in a bit of work for I guess replay protection. So it is safe as long as they do the work and get consensus, and is needed. And yet they had no interest in doing it.
It is not 'safe'.
It can not be regarded as safe without proper testing.
Btrash Bcash forked and increased their blocksize to 8mb without proper testing. Their network has still not been tested yet.
You can't predict how the whole network reacts to 8mb blocks. The network latecy. The increase in processing time for every node, the eventual abrupt termination of processes inside a node because the I/O operation took 8x longer than before.. you just don't know.
Without a testnet and proper testing over a long period the majority of btc user probably wouldn't support such a massive change in consensus rules.
So that should tell you that any increase in block size in the future, no matter how bad fees get, is unlikely to happen, at least not while the current devs are in charge of bitcoin's path forward.
Bitcoin does not have any 'devs'. It is a community driven project.
The user decides which consensrules he follows.
If you think you can improve bitcoin, do it. Make it better, convince everyone why it is better and maybe the majority will follow your 'upgrades'.
On chain scaling is of course only part of the solution. LN is the main thing that will open up the ability to use Bitcoin as a payment network, but it relies on having space in the blocks to perform the channel openings and closings, so the number of people who can use LN and there bitcoin is entirely dependent on the size of the blocks..
No. You got that wrong.
It does NOT depend on the size of the blocks. It does depend on the
amount of transactions which fit into a block.
The amount of transactions can be increased with a bigger block size. But saying 'it is entirely dependent' is just wrong.
Segwit for example introduced weight. On average there are about ~2,2 times more transactions in a block now.
With 100% segwit usage there would be 4x more transactions inside a block compared to legacy transactions. Without a hardfork.
Really the perfect time for a hard fork to increase the block size was the past few months during the crash when interest was at a low point. By the time the masses come rushing back in next year they could have found segwit fully adopted, LN available and growing, and block size larger to allow the network to grow even that much more.
No, it wasn't.
Why increase the blocksize with a hardfork (and risk getting just another btrash coin) if fees are at 1 sat/B for 1 block confirmation? Can't get lower..
At this point Bitcoin is pretty much guaranteed to be constrained to the 4 million block weight forever.
Maybe, maybe not.
Only time will till which innovative technologies appear to strengthen bitcoins functionality.