You're not the only one, and I agree with what you're saying. I also think a menu that allows filtering by language would be a good idea.
A tip: when I want to search for games in another language, I use the URL:
itch.io/games/lang-<CODE>
Where CODE is the 2-letter ISO code.
To search in German, it would be:
itch.io/games/lang-de
For Spanish:
itch.io/games/lang-es
The great thing is that when you're on the games page with the language selected, any other filters you use are automatically added to the language filter.