PMFJI but I wanted to point out the default in Mail is to send large attachments via Mail Drop and the size limit is 5GB. While I am aware of your reluctance to use iCloud, but, instead of using email attachments consider iCloud File Sharing. It is very secure, iCloud is encrypted, iCloud file transfers are end to end encrypted, you can share the file with "anyone that has the url" or "only those you invite". Videos will not "stream" from the cloud, but they will download easily and file sizes can range all the way up to 50GB.

If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein