Yes, text visibility is a ranking signal, according to official Google statements. The way text is presented in the interface, visible VS hidden text, affect how much weight is assigned to text.
The official Google documentation recommends making important content visible:
“Make your site’s important content visible by default. Google is able to crawl HTML content hidden inside navigational elements such as tabs or expanding sections, however, we consider this content less accessible to users, and believe that you should make your most important information visible in the default page view.” source
This factor is tricky to asses because Gary Illyes twitted this a bit different:
AFAIK, nothing's changed here, Bill: we index the content, its weight is fully considered for ranking, but it might not get bolded in the snippets. It's another, more technical question how that content is surfaced by the site. Indexing does have limitations.
— Gary "鯨理／경리" Illyes (@methode) September 14, 2018
As of 2018, what we know for a fact is that if a site is included in the MFI (mobile first index), content behind tabs and accordions will be given full weight.
no, in the mobile-first world content hidden for ux should have full weight
— Gary "鯨理／경리" Illyes (@methode) November 5, 2016