In a vacuum this must be true, but I don´t think the concept of 'grammatical case' works well with agglutinative languages. Hungarian's 18 cases might look scary but they follow a learnable pattern, on the other hand, Latin's 7 cases seem to be a nightmare to memorize

For Romance speakers, Latin is definitely easier since you're already familiar with its vocabulary. So it's mostly a matter of getting used to the case/declension system.

Latin is literally the easiest language in the world because 90% of "main words" came from Latin.
Hungarian is super hard to learn