Domain per country/region or one for all versions and countries?

Question

Search Engine Optimization

Friends! Desperately need help.
There is a literary portal (content - books and any literary party), there is a question of entering the markets of several other countries (now we work only in Russia). There are two conflicting opinions:
1) Ideally, for SEO, there should be one domain per country, or at least for some region / language. Because there should be one language on one domain, which is tied to the domain, and not determined by the settings of the logged in user or his IP address. Otherwise, the search engine will not be able to properly index content in different languages. And the site will be cool in the main language version (for example, English), but in others it will lose.
2) It is better to make one global domain and, for example, launching in some new country, it will give trust and in general all versions will feed each other and the rating will accumulate strongly in one place, and not be scattered over a bunch of domains and this is better.
Where is the truth?
And if you organize within one domain, then how is it better to do it:
- subdomains by country,
- subdomains by languages,
- segment in the url (first segment) for the country or language,
- without displaying in the url at all, but only by IP /cookies for unauthorized and account settings for authorized users?
Where are the pitfalls?