To us (germans) learning english was easier in the beginning. Not necessarily because words were often alike (sometimes the same words have different meanings, "false friends"). But of course in contrast to french, one does not have to learn conjugations, gender of words, etc.
But after having reached an intermediate level of both english and french, things started to change. Perfecting your English skills progressively gets harder, whereas after ~3 years you had completed the whole french language.
As it turnes out, English is huge. The english dictionary is huge. It is basically the size of the german dictionary and the french dictionary combined, as it draws words from 3 main sources French, Old Saxon and Scandinavic, and then was happy to incorporate words from all over the place. So you have the word "hunger" (germanic root, compare german "Hunger") and "famine" (romance root, compare french "faim" meaning hunger and "famine" meaning famine). To this day, using english on a daily basis and reading many english books, I see a lot of words I have not yet learned.
The next "advanced" difficulty is that of idioms and idiomatic usage, english is full of idiomatic phrases. Something like "to get it over with", "to make ends meet". Learning such idiomatic phrases is difficult but necessary to reach an intermediate level of english.
At the same level, learning French, one can perfect one's pronunciation (to the one, official pronunciation), catch up on a few corner cases of the conjugation system and enjoy having mastered a language.