Its alot easier to be frum in the US because of people like Rabbi Heshel.
Until the 1960’s relgious rights were somewhat limited. While its true you could get a new job everyweek at some point many people gave up and eventually worked on Shabbos.
The US army did not have kosher provisions and while some tried (and did keep kosher) many were not able to.
Things like leaving work early on Friday was unheard of. Money for Yeshivas (There is indirect money and lots of it for stuff like books, School buses and more)
You needed people to get the laws and attitude in the US to be changed in order for frumkite to exist.