Maybe it's not when writing plain English, but as soon as you want to include tricky Unicode characters it's not anymore. I spend hours trying to fix bugs for

Maybe it's not when writing plain English, but as soon as you want to include tricky Unicode characters it's not anymore. I spend hours trying to fix bugs for my master dissertation and gave up with two unfixed problems: (1) missing line breaking in references containing accentuated characters and (2) including some non BMP code-point character. And some package can mess up with some other packages so coming with a solution can sometime break another thing.