Destructible environments were in Space Invaders in 1978 :p However can you imagine what Crackdown promised, without the cloud, in a full scale world. Fast read/write access will make it possible to have large scale completely destructible/alterable worlds, shape the terrain anyway you like without limits. Yep, can't wait to see where games will take us next.
That is all entirely possible now, it's just making the assets takes time and money.
Just keep in mind that many of the promises people are "proclaiming" to be coming next-gen have been many of the same promises we have had every gen.
You can also see it like this. HDD is like dial-up, SSD cable/fibre. Why keep making games for dial-up internet.
It's pretty crazy to realize that the fastest home fibre internet you can get atm 1 Gbps, is faster than reading from HDD. Your download speed is actually limited by how fast the HDD can write the data to disk... My laptop HDD topped out at 640 mbps read speed.
1Gbps is "Giga BITS Per Second". - There are 8 bits in a byte.
1Gbps thus converts into 125MB/s. - I have hard drives that are faster than that.
640Mbps equates to 80MB/s. I have had Laptop hard drives that are faster than that.
Now 10 Gigabit ethernet/internet will definitely hit some mechanical disk walls... However keep in mind that internet tends to function on latencies measured in "Milliseconds" rather than "Nanoseconds" of a mechanical disk, so a mechanical disk still has significant advantages over high speed internet connections.
Either way, the storage is entirely redundant if you can fit everything into Ram anyway.
Yes, there are faster ones, I'm just using the benchmark crystal disk gave me for my laptop, 79.92 MB/s sequential read speed, hence 640 mbps. Avg is 100 MB/s. HDDs are also CLV so it also depends on whether the data goes on the inside or outside edge.
RAM is always a constraint in consoles and the increase from this to next gen is rather little. However thanks to SSD a lot less will need to be kept in RAM. Consoles can't fit everything in RAM.
Crackdown apparently wasn't possible now (as promised), it kinda sucked compared to the tech demos early in the gen. Internet latency and having to compress down to 1.5 mbps were likely the main reasons. That 44.2 terrabits per second internet will also not help game streaming as long as latency and jitter are still an issue, but it is interesting to see what can be possible in the future. At least image quality can vastly improve for streaming.
Anyway it was just an analogy, HDD = dial up speeds, SSD = cable/fibre speeds.
Can you play Fortnite on 56K modem... Of course somebody tried lol