The cost of data egress from the cloud really limits its potential for most HPC applications, though. The "free" or reasonable-cost tiers are okay for small-scale toy use, but not much more than that.
For academia, all 3 major cloud providers have a data egress waiver - meaning that as long as data egress is less than 15% of the total bill then it is free.
Combine this with the fact that S3/Glacier make much more sense than local HDDs for long-term archiving and egress turns out not to be a significant factor in my experience.