Is there any alternative for the Redactor plugin in Craft 3? The Redactor plugin not working well for me. So I am in need of another good plugin for an editor that supports HTML, image, video, etc. 

Please advise me about this.
Rakhi, based on your comment on the question, you're missing the video and imagemanager in the plugins array.

Example:

"plugins": [
    "alignment",
    "fontcolor",
    "video",
    "imagemanager",
    "table",
    "fullscreen"
],


Read more about it Here and Here