It was truly no better than league one level not that long ago. Now it’s definitely close, or on a par with the championship. Which is no insult at all. Plus it generally has some nice stadiums and playing surfaces. Even if there are a few artificial turf abominations.
Still, the NYC FC game cited above, all the goals came from errors. The first an own goal. The second a howler from the keeper. The third the right back completely asleep at the wheel. The quality still isn’t on a par with even the lower tier European leagues, but the general play, and as an aesthetic spectacle, has improved greatly. And it’s no longer a cause for mirth or patronisation.
I think the greatest improvement has come from (a) the pace of the game becoming much more demanding, and giving it a uniqueness similar to the PL in style, and (b) the move away from aging European stars on a retirement tour, and instead recruiting more emerging talents from South America. It’s slowly becoming a breeding ground for European clubs to scout. Which is only good for the league. It means it’s started to be taken seriously.
The fact we are seeing coaches from there come to European football should speak volumes about how much more sophisticated the league has become.