Is it hard to become a SEO freelancer these days?

Hello there everyone!

I heard from a lot of places that nowadays it is much harder to master the skill of SEO than it was some years ago

I know that you can basically never become an SEO expert, because it is so dynamic and there is a really deep rabbit-hole; but after how much time of practicing do you think you can start being a freelancer and looking for potential clients?

Do you also think it is profitable to start SEO freelancing?

I am really curious on learning the skill, as I am highly interested into going on the freelance path, so can you recommend some good courses/books where I can learn the basics and then start practicing?

Thanks in advance, chiefs!