Nuclino is described as 'Unified workspace where teams can bring all their knowledge, docs, and projects together in one place. It’s a modern, simple, and blazingly fast way to collaborate, without the chaos of files and folders, context switching, or silos' and is a very popular Note-taking tool in the office & productivity category. There are more than 100 alternatives to Nuclino for a variety of platforms, including Web-based, Windows, Mac, SaaS and Linux apps. The best Nuclino alternative is Obsidian, which is free. Other great apps like Nuclino are Notion, Anytype, Trello and Notesnook.
If you like Google products that is your best Wiki. It has the same scope as Nuclino but fits much better into Google's ecosystem.