Spinning rust is still the only cost effective answer to redundant 10+ tb storage. If you have 4+ disks, use raid 6 or raid 10 and you get decent fault tolerance too. Raid 10 also increases write performance but it's a bit less robust imo and more expensive per gb.

As for speed it's mainly tied to rpm and the market decided no one wants higher failure rates / lower mtbf for marginal speed gains.

If you need speed and capacity, throw an ssd or two in front of a raid disk array for caching with primocache or whatever.