Now I'm in doubt about something. I saw yesterday Paypal and Visa retreated their partnership with facebook's Libra (Diem) due to politicians and regulators pressure, but now I see the same two giants are adopting bitcoin?

Without any doubts the interest for crypto currency is huge, however I see some inconsistencies between the news.
It is actually very simple. Libra project is different from Bitcoin. Bitcoin was an original innovation, created by Satoshi Nakamoto in 2008 and first mined in 2009. On the other hand, Libra plagiarized around 95% of the idea (as well as the code) from Bitcoin and tried to dish out their own version of the cryptocurrency. It is similar to what the Chinese used to do two decades earlier. They purchased a couple of Su-33 fighter jets from Russia and then plagiarized it's design to create their own jet (J-15). To their credit, the Chinese exported far more pieces of J-15, than the Russians could ever do with their Su-33. Facebook wanted to do the same, with their Libra shitcoin.