There is an app on android called Video Downloader to pirate videos from websites. Now, it works for almost every website except youtube. The problem with this app is, it has no adblocker and when you visit sites you should not visit without an adblocker, it just rains ads on you. So, is there a website equivalent of this app which can download videos from any website?
They already suggested
yt-dlp, but also have a look at JDownloader. You can paste a webpage url and it will fetch all the elements it can download, video included. You can also create download collections in order to download the same files again (or in another computer with JDownloader installed).