It's better to read a book than to see a film version

I strongly believe that people should prefer reading books instead ofover watching films.

Your original sentence is perfect grammatically, but I think maybe this corrected sentence would express your meaning better? With your original sentence, it kind of suggests that you think people shouldn't watch films at all. However, I think that perhaps what you want to say is that it's just better to read books than to watch films (but someone doesn't need to avoid watching films completely?).

Books are often more compelling, as they enable readers to create their own world, and they convey an original message wholly.

Without the "as", your sentence becomes a run-on sentence - basically separate sentence phrases that could be split into two sentences.

I also think the last part should be changed to "they convey an original message wholly" to make things clearer. You're referring to the books conveying the message, right? It's confusing because without it, it seems like the sentence means "they enable readers ... to convey an original message."

First of ally, reading requires more time and effort, and this is why this activity is more creative.

"firstly" is not commonly used; better to use "first of all", which sounds more natural

There are no other people, directors, or actors, with their own vision that may not coincide with what you are imagining and feeling at the moment.

"imagining" might be a slightly better fit than "feeling" here, when talking about a book

Secondly, plots in films are often abridged because of time limits.

Your sentence is grammatically fine, but for this kind of argument, it's better to acknowledge that this isn't always 100% the case, so I added "often." I think it's possible that some film adaptations actually succeed in not abridging the plot!

A great amount of nail-biting moments canmight be omitted from the film.

It's good to be more specific, so I added "from the film." I think "might be" is also more appropriate to use than "can be" in this case.

As a result, films aremight not be really faithful to the original books and not as captivating as they could be.

Finally, some film-makers see the acting stage as a place for solvaddressing social problems.

"Addressing / commenting on social problems" is probably closer to what you mean... I don't think filmmakers think that they can fully solve social problems through films; more likely, they use films as social commentary.

This is howwhy a huge number of people of different races and genders started playing in films.

The thing is, that they don’ey may not match the characters’ description in the books, so spectators can experience some discomfort.