You're just ignoring all the facts.
There are 211 international teams.
Only a small fraction of these have squads that consists of many players from top clubs. And even in the top ranked 20 teams, you'll find a bunch of players who don't play for any of the best teams in Europe, let alone the very best teams. Many of these players play for relegation fodder clubs across a multitude of leagues of varying quality. Heck, some of them even play for lower division teams.
The rest of the international teams mostly consist of decent to average players, to downright semi-pros, not to mention a bunch of amateur footballers that literally have regular jobs when not on international duty. For every England, Germany or Argentina, there are dozens of teams like Peru, Canada, Mali, Faroe Islands and Vietnam. How many Faroesw players can you find in the genuine top teams across the world? Yet they all compete together in their respective qualifiers. Even bad teams regularly qualify for the World Cup and Euros, because they play even worse teams. So you'll always get a team like New Zealand or North Korea in these tournaments. Not to mention all the mediocre dross in between.
So of course international football isn't the highest level. A vast majority of these teams wouldn't even hack it in League Two.
And that's not to yet again mention the drop off in speed and intensity you get, even amongst the better teams. Look at England play, and compare that to the average Premier League game. It's night and day with regards to the general tempo and intensity. Y'know, that which actually makes football such a difficult game, alongside complex tactics, which also are lacking by the sheer necessity born out of almost no time to properly train and prepare for games, compared to a club where it's your full time job to train and improve tactically every day. But you can of course just ignore all that again, and convince yourself of a different reality.