SSD is fast and quiet, but a regular old HDD will do the "home media" collection storage & streaming job just fine. It is not a high demand thing to flow video from even a slow drive. And obviously, it's much more economical too. Pricing of 8TB SSDs tend to be running north of $700 on a good day. $700 would buy several 20TB HDDs so one could have one in active use and 1 or 2 more as media library/Time Machine backup drives (of size).
If cost factor isn't much of an issue, yes, get 1+ 8TB SSD(s). But if it is a bit of a stretch, buy a much bigger HDD or 2+ for the same budget and have plenty of storage for the future, backups, etc.