These tweets are pretty rubbish, why would someone think that they should earn the same salary as someone else? Salaries should be different even in the same company, that way people are then encouraged to work and study harder and to better negotiate and know their value. But these tweets are even worse and it's comparing different companies and countries.
This is just a spreadsheet of tweets that share salary info, where do you see an implication that everyone should earn the same salary?
I believe this is intended to help people negotiate. Those of us who have a network of friends in tech get this information informally that way, but salary sharing like this gives people who don't have that network a starting point (albeit one riddled with selection bias and low sample size).