There's little performance advantage to SSDs over hard-disks since the proof of space only requires a few blocks to be read every (on avg) 5 minutes. This leaves them unable to compete against the much cheaper hard-disks.
Furthermore, the ROI on hard-disks bought just to mine this may be decades as there is already a glut of unused hard disk space. So there's no hard disk shortage to be expected.
As downsides to chia I see
1) the huge premine.
2) the large complexity of the proof of time + proof of space system.
3) the fact that the mining chain cannot commit to the tx history (instead the miner's private key signs for a block of txs as belonging to the mined header)
I'm really hoping this doesn't gain momentum. It's difficult to imagine how artificially increasing the demand for hard drives could be a net benefit for the world.
As downsides to chia I see
1) the huge premine.
2) the large complexity of the proof of time + proof of space system.
3) the fact that the mining chain cannot commit to the tx history (instead the miner's private key signs for a block of txs as belonging to the mined header)