Those other coins could set their blocks to 1 GB per block, but it wouldn't make any difference in practice if the demand isn't there. But if Bitcoin increases the size of its blocks, even a little, people are likely to use that additional space and the overall size of the blockchain could grow even faster than it currently is. That's why non-mining full nodes on this chain are being cautious and not permitting larger increases.
and thats the point
using fear of gigabyte blocks to suggest there actually would be gigabyte blocks was the empty argument
when bitcoin went from 0.25mb to 0.5mb, then to 0.75mb and then to 1mb... it was not an instant jump. even with the availability, it was a curve of natural growth.
its like buying a computer with X ram
if you know the pc needs 2gb ram for the OS. you dont just buy a pc with 4gb ram knowing as soon as you install office and an antivirus your at a limit as soon as you open the tabs up.. you instead buy a PC with 8-16gb ram knowing that theres is available spare space(buffer) to allow for growth without having to instantly complain you hit the limit soon after.
core keeping legacy down but trying to promote the LN gateway tx format is not to inspire bitcoin utility growth/adoption. but purely to inspire not increasing bitcoin utility and infact decreasing bitcoin utility while trying to promote deburdening bitcoin network in favour for other networks
and dont rebut that 'non-mining full nodes on bitcoins network are being cautious and not permitting larger increases'.. as the foolish thing is those very same people allowed a contentious hard fork in summer 17, allowed hard drive bloat to increase, allowed new wishy washy code. yet non of which actually caused a increase allowance of legacy tx throughput.. thus that was not 'cautious' that was 'cunning'
and dont rebut that 'non-mining full nodes on bitcoins network are being cautious and not permitting larger increases'.. as the foolish notion that nodes are being economic majors and wanting to aid mining pools to earn more fee's by having a fee market.. when mining pools if they really wanted to earn more would only accept tx's of $1 and force users to pay more. but instead some pools throw any transactions in randomly and some do empty bocks which mean pools dont care about fee's