Learning Kanji isn't really all that bad and there are only like 2,000 or so to remember, and if you forget one occasionally you can write in hiragana, which is very consistent.

Lao, Thai, Burmese and Khmer scripts, whose writing have the same origin, and have many similarities. The pattern of reading can be a bit tiresome because of how vowel and tone marks are laid out, and they all have complex systems of how they fit together.

Chinese has a lot of characters, but there are patterns in them because most have a phonetic component, and there are only a couple hundred syllables used in most Chinese languages. It's not terribly different from English, which doesn't really follow its phonetic system too well, and most English speakers have to rely on memorization of word components, so we know with "ough" not to pronounce "gh", as well as the "ou" is different depending on the word, e.g. "through" vs. "dough".

I think people just get little overwhelmed about having learn a new way of writing, but once you get used to it, it seems completely natural.