Trying to get some old MP4 home videos into iCloud photo library. I'm able to get them in there but surely it doesn't have to be this complicated?

I have a bunch of MP4 videos I made years ago when capturing some home VHS tapes.

I'd love to get them to be playable in my family's shared iCloud library, but as I understand it, there's a 15 minute limit there. OK, but I should at least be able to get them into my personal library, right?

And I can, but the only way I've tried that works is first manually uploading them to iCloud Drive via my windows desktop (MS Edge), and then on my iPhone I long press on the video and choose 'share' and then choose 'save video', which places it in my personal library (which I can then place in the shared library if the video is under 15 minutes).

But if I try to import the video directly to my iCloud Photo library via my browser, I get the error "There was a problem uploading 1 photo. Your file must be smaller than 100MB"

Now, I notice if I hit the 'upload' button on iCloud.com, it filters down to only JPEG file extensions. To me that makes no sense, since iCloud Photo library supports far more than just JPEG file types. In fact that explicitly state they support MP4 files. And they do, if I go about it in that convoluted way I described.

I also tried iCloud for windows as a way to push the MP4 files up and it just ignores them. It acts like there's nothing there to upload.

I feel like Apple *sometimes* has good explanations for their design decisions, and this feels intentional.. so maybe there's something I'm not getting conceptually here?