If you want a web-based tool that's easy to use, Voxweave is a good option. It offers a simple interface to generate summaries, subtitles and mind maps from YouTube videos. It can translate video transcriptions into more than 30 languages, and it offers a few subscription levels so you can use it at a level that's right for your needs and budget.
Last, Nobinge is a powerful system that summarizes YouTube videos but also offers polyglot language support for more than 80 languages and can convert text to speech in 57 languages. It also offers an AI-powered tutor for 24/7 Q&A and supports other media formats, so it's a good option if you want to manage content.