you should have been learning French as mother tongue in Switzerland. When you have to learn as child Ancien Greek, French; German, English and Italian at the same week. you will find English easy. It's extremely difficult to write in French accurately because it's not a phonetic language. It exists also spelling contests. Napoléon Bonaparte made in his time about 80 spelling mistakes !
I would say English was not that hard for me but that's probably because I am European, and even more French since the English language contains around 30% of French. So it makes it easier to memorize vocabulary etc. But for, for exemple, asian people, it must be harder since the pronounciation, grammar and vocabulary has nothing to do with most of them...
As a native speaker, I can confirm. None of the rules are universal, the pronunciation has shifted dramatically since the last time spelling was standardized (like 400 years ago), half the vocabulary comes from a completely different language family. Even with over 20 years of practise I still screw up perfectly ordinary sentences.
Actually, I speak a North American dialect, so I use that weird r sound where you bunch up the middle of your tongue toward the back of your mouth. It takes some kids YEARS to learn how to do that properly. One of the most common sounds in our language, and some native speakers don't master it until they're in middle school. Awful hodgepodge mess of a language.
I think any language is hard to learn. All the vocabulary and the tenses and the grammer rules tend to get messed up and scrambled in your head when it's not your first language so it can be confusing at times, especially when you already have more than one language in your head already. I think English is difficult even for native speakers. I'm like 95% fluent in English and i still make so kany mistakes with everyday words because while something like soeaking may be easy, the spelling rules don't always make any sense and because of that, i get confused and make mistakes, but its ok. That's how I learn. Anyone who learns a language because they want to amd not because it's something they have to do like for school or something should feel proud of themselves because it's hard but not impossible