You could host your own if you have the hardware to spare.

Archive.org and a donation if its that much. Or your own instance. Most instances cant accommodate that much data unless you are willing to donate.

Ask their university or institute to provide them with some webspace and upload it there. It's their job to provide the scientists with tools to accomplish their work. Or apply for a EU grant or something for a central instance. I don't think it's sustainable another way because it's going to cost someone around $5 each month to keep 200GB of storage around. Say "many papers" is 15 and they're on average 200GB, that will be $800 a year someone has to pay (if my maths on AWS is correct).

Plain webspace or storage space has the additional benefit it won't get re-encoded or compressed by Peertube/Youtube. Depending on the exact use-case, other scientists might want to get the original data anyway. And some universities already have video portals, though usually for conferences, lectures etc.

Edit: Other than that there seems to be the TIB AV-Portal, not Peertube but pretty much what you're asking incl long-term archival: https://www.tib.eu/de/themen/wissenschaftliche-filme I don't know but I suppose scientific journals or university libraries might have storage available as well for attachments to publications.

The archival is done on someone else's computer, so someone will have to pay for storage and the services for making it publicly available. And even the person that believes everything should be free will start reconsidering once the instance's bill arrives.

My suggestions are either making it available 1) on a self-hosted Peertube instance, 2) on an instance after an agreement (potentially even a financial one), but that requires reaching to the admins of each instance considered, 3) through torrent, 4) on archival sites like Internet Archive, 5) on more profit-oriented Youtube competitors like Odysee and Rumble if your friend must avoid Youtube, as those could probably endure a few potential TB of data more.

Sounds like a lot of data. I know of videos.trom.tf "A trade-free video hosting platform for science/technology/nature videos in the English language. You do not have to trade your currency, data, attention, freedom or anything else, in order to use it."

They 'host' a huge collection of science documentaries and other 'enduser' level videos, but may not be interested in research level storage if it's terabyte upon terabyte ? He could ask them, and perhaps get a suggestions for other science hosters that have a larger backend ? Maybe they are seeking out each other in a network.. Worth trying I think..