I have read in other discussions that having all questions on an FAQ page is the way to go and then if the question has an answer worthy of its own page, you should abbreviate the answer and link to the page with more content.

My question is when using some templates in WP, they have a little + button you can click and it reveal the answer to the question. Does this hurt SEO versus having all text visible and then using headers/subheaders?

An example of the + button https://fyrfyret.dk/faq/