Weird that no service provided by seznam.cz is listed (I would expect at least their maps or email to be mentioned, while the search engine is tailored to czech language only so listing it would be less useful to most people outside of Czechia).
Self-diclosure of bias but they also missed our independent no-tracking international search engine (own crawling/indexing) https://blog.mojeek.com/2021/05/no-tracking-search-how-does-...
So does Seznam.cz search engine, which, I believe, has it's own crawler and rankings.
Email.cz is used by the most of Czech citizens. When someone asks you for an email address, it's common to reply with the username alone and just confirm it's hosted on Seznam.