Most of them don't. Beskar is very rare, and Jango wasn't into any of the Mandalorian shyt by the time we meet him in Episode II. The government of Mandalore also disavowed him in the Clone Wars cartoon.
This x100. Favreau deserves credit for advancing Lucas' technological innovations and probably having enough weight on him to not get bossed around by Kathleen. The story/lore is
all Filoni. This is obvious in the GALLERY documentary on D+. Whenever he starts talking about the lore of the Lucas films everyone else, including Favreau, shut up and go
George Lucas is the Star Wars God, Filoni is the chosen one bring balance back to the franchise.
If you watch this on D+ you can see Favreau
and the others, including Kathleen Kennedy just
. This video even explains exactly why Ahsoka refused to train Grogu in the last episode. She didn't have that Qui-Gon in her just like Obi-Wan didn't in the prequels. And it basically explains what Filoni/Favraeu are trying to recreate with this show.