I think it’s not as much difficulty rather than the fun in learning a language. I recently took a year of French (A1) and am a couple months into a Japanese course, and I have a lot more fun with Japanese, even though it should be harder. There’s a lot of fun in learning katakana and hiragana, and sites like Wanikani help make kanji learning really fun too.

That being said, yes the progress is a lot slower in Japanese. In French I could make some pretty long complex sentences relatively quickly. In Japanese it’s still things like “Mary ate breakfast in a cafe and watched a movie with a friend on Saturday” after 5 months. In my French class we did stuff like that maybe 2 months in (though we stayed in the present tense a lot longer).

Overall I think if you have fun the difficulty doesn’t matter. Good luck if you have to learn a language you don’t like though.