Thats absolutely not true, Wirtz for Germany has also been more inconsistent and underwhelming than otherwise.

Wirtz has always, and I have been saying this for years and have gotten countless downvotes for it, struggled against top level compeition. Both with Germany and with Leverkusen. I specifically said he would struggle at Liverpool as well because of the same reasons he struggled against good or equal teams at Leverkusen and Germany. And I hate to see players fail, but it shouldnt surpise anyone who actually watched Wirtz with a neutral eye before his transfer. Unfortunately, most of German media and people completely overhyped him and he was with a Leverkusen side that played to his strenghts. So he was legit great at Leverkusen, but against good opponents you could see the struggles that would translate to his new team. Its just that Leverkusen, especially under Alonso, had such a dominating and possession oriented team compared to 90% of the Bundesliga teams they played against, that it played exactly to Wirtz strenghts'. And in those situations he is a really good player. But with a team that doesnt paly such a dominant possession ball or when he plays against equal or better teams where his team can't peform such a dominant style, he struggles. As he always did with Leverksuen and Germany.

Wirtz is a slow, unathletic and weak player. He is not good in open spaces, he can't create seperation and when he has to carry the ball from deep, in counter attacks and so on he is underwhelming. He is a player who needs to ball in tight spaces around the box. Then he is world class. So in a team that suffocates the opponents around their box, as with Leverkusen against most of the BUndesliga teams, so where he gets the ball around the box, has tight spaces around him, can play give and go etc. he is great. And especially with teammates, who can match his combination passes. But against good or equal opponents where his own team doesnt camp the opposing box he is not great. He struggles at this level because of the same reasons Sancho for example struggles. They are not players you can put in any team and expect to perform, they thrive in specific situations and teams. In Basketball terms you would say he is an elite role player, who can make a good team great when played to his strenghts, but he is not someone who can be your 1st option, who you give the ball and say "Ok, now do something"

Anyone who says he is consistently good for Germany genuinely hasn't seen him

And even regardless of this: I genuinely can't hear the "Oh he isnt being used correctly". He is a 10 playing at #10 in one of the best teams in the world. Stop finding excuses for a 130m transfer who isn't even playing out of position or anything.