I spent a decade toiling along in the range of ~$65k to $118k CAD.
The thing that opened my eyes to the fact that 4x and 5x salaries are possible was people posting honest descriptions of their salaries and places like levels.fyi.
I am incredibly thankful for the people who went before me in terms of being open and honest about how much they can make as a software engineer if you just choose the right company.
I don't think "humblebrag" is an appropriate response to this person's message since it might have a chilling effect on their decision to publicly say stuff like this in the future.
... and at least from my perspective people saying this stuff is quite literally life-changing.