Personally, I would prefer the traditional way of publishing. The problem is to find a publisher without paying for the publication. See also:

https://www.researchgate.net/post/Have_you_had_experience_with_self-publishing_a_textbook/1

https://www.researchgate.net/post/Publishing_books_on_Amazon/1

https://www.researchgate.net/post/Self_publishing_is_worth_it_in_terms_of_my_future_career/1

https://www.researchgate.net/post/Which_is_the_best_and_reliable_platform_to_self_publish_ebook_free_of_cost/1

Be warned of publishers like Lambert and Eliva Press:

https://www.researchgate.net/post/Opinion-required-on-Lambert-Academic-Publication-is-it-okay-to-publish-thesis-through-them/1

https://www.researchgate.net/post/Is_it_worth_publishing_with_Lambert_Academic_publishers/1

https://www.researchgate.net/post/Can_I_trust_to_publish_in_LAP_LAMBERT_Academic_Publishing/1

https://www.researchgate.net/post/Lambert_Academic_publishers_Truth_or_falsehood/1

https://www.researchgate.net/post/Is-LAP-LAMBERT-Academic-Publishing-is-an-authentic-publisher/1

https://www.researchgate.net/post/Is_it_worth_publishing_with_Omniscriptum_Scholars_Press_or_is_it_just_plain_scam/1

https://www.researchgate.net/post/Does_Eliva_Press_legitimate_Is_it_worth_publishing_a_book_with_them/1

https://www.researchgate.net/post/Is_Eliva_Press_SRL_legit_to_publish_your_article_or_research_papers/1

See also these discussion on printed books vs. eBooks:

https://www.researchgate.net/post/Will_paper_books_ever_vanish

https://www.researchgate.net/post/Which_is_it_better_to_have_an_ebook_or_hard_copy_book

https://www.researchgate.net/post/Printed_books_or_e-books

https://www.researchgate.net/post/Can_the_eBook_replace_the_conventional_printed_textbook_What_do_you_prefer_and_why

https://www.researchgate.net/post/What_kind_of_publishing_of_scientific_monographs_do_you_prefer_In_printed_form_or_in_the_form_of_an_e-book

https://www.researchgate.net/post/Do_you_think_eBooks_will_replace_printed_books_in_the_near_future

https://www.researchgate.net/post/Do_you_think_that_there_is_no_need_for_the_printed_version_of_any_journals_issues_Since_we_only_use_electronic_copies_for_reading

https://www.researchgate.net/post/Do_you_think_print_course-books_are_more_effective_than_e-books_or_other_kinds_of_multimedia_teaching

https://www.researchgate.net/post/Are_Books_Going_to_be_replaced_by_Technology