meh, i dont think international teams have been playing long enough for that claim to be justified
the four big eras that really have existed in csgo just happened to all be one country teams, and each of those teams had to grind just as much as any other team did before their success really popped off. the nip guys had grinded from cs 1.6 to csgo and hence dominated the early stages, fnatic needed a few years but eventually they started winning most things (but the players had been playing since 1.6 too), the core sk guys would have known and played with each other years before they all merged, and many of the those guys had been playing since the early days of cs. then we have astralis of course who is the best example, they had all been playing since the start and lost constantly, it took the core many years before they managed to neatly tie it all together with gla1ve.
only in recent years has it become economically viable for people to travel the world to play csgo, so one country teams have had such a big head start too.
and even then its still steep if ur not gonna be performing, whereas in other esports its a lot more common to see tier 2 and 3 players move overseas cause the game is much more viable financially
and for all the shit that faze gets, they've won plenty of tournaments over the years, or at least made high places in the playoffs
you dont need an 'era' to be a good, long-lasting team but i dont think faze is a good example because the org is really trashy and the mentality just isnt there to actually make proper moves in csgo esports with sustainability in mind