Generally speaking, MLS is competitive with Liga MX on roster spots 1-5. In players 6-11 there is a pretty significant drop off, and the bench depth isn't even comparable. More than anything that has to do with the depth of the US and Mexico player pools. Although the US and Mexico have a comparable number of EPL/Bundesliga/La Liga quality players. The number of Mexican players that are just off that level is significantly higher than the number of American players...and the domestic leagues reflect that.
So once in the last 15 years has a top European country played a friendly against a non-European country outside the top 75. You think that's solid evidence that we should be able to get multiple a year?