If giving access is the problem, then you can (instead of making a platform), make a script for a Digital Ocean droplet, for example.
1. Setup 5 or 6 dollar droplet.
2. Editor uploads to the droplet. It is processed and validated by script. Code script that only allows X uploads in X hours.
3. Script can keep the video in the queue and give the creator a link to view the video to the droplet (VLC remote link) OR/AND Script uploads to YouTube and sets the uploads to unpublished (defaulting to private). (https://developers.google.com/youtube/v3/guides/uploading_a_...)
4. The script sends the creator or gives back a link to the editor to the video and the creator can review that video while on YouTube and while it is being encoded for all resolutions.
5. If a creator likes the video, then they themselves can schedule the publish date, and publish to YouTube.
6. Allow script to be updated over time for changes in API. Editor only needs to upload once to server. Creator downloads nothing. Also this server can auto backup the video for an archival solution to wherever else (but that is a story for another time).