Just because thousands of words have fallen into disuse does not imply that English has become 'easier'. The purpose of any language is communication, and as society changes, the things that we wish to express also change. It is therefore inevitable that any language, let alone English which is so widely used, will be in a state of constant flux.
English is no easier to learn, today. If 10 words have gone out of usage, another 10 have come into usage. It is just as hard to write good, expressive English today as it was 100 years ago.
But the amount of English spoken around and written around the world, definitely exposes people to a lot of English. So, it might be possible to pick up the language more easily just because so many people use it. So, it might have become slightly easier to learn, just because of its immense popularity.