AFAIK problem with all physical energy storage solutions is just one of cost.

Batteries are scheduled to become so cheap that these type of physical storage systems just won't be able to keep up in terms of cost.

Most pumped hydro projects are now put on hold as batteries have been coming down.

I've recently learnt about sodium ion batteries, such as this uk company:

https://www.elevenenergy.co.uk/#sodium-ion

They are larger than lithium batteries, but potentially cheaper and better performing around temperature extremes.