My last contract we wrote a c tool that did dsp on 10tb/day data with a latency of 50 microseconds. We are using less than 10% of the CPU on that.
At a price of $2500 once for the TR versus $24,000 per day for cloud, it's a no-brainer to buy them. Sadly, availability in my area is pretty spotty and even Amazon currently predicts 2+ weeks of delivery time.
Threadripper 3970x = 32 cores @ $1999
AWS c5.9xlarge = 36 vCPUs @ $8.34/day (spot)
You could buy a year of AWS for the same price as a Threadripper based PC.
For EC2, one would need to rent licenses for the V-Ray renderer plus V-Ray tends to be heavily CPU-cache- and memory-bound, so exactly the parts that get slow if you enable the Intel security fixes. Due to c5.9xlarge being Xeons, they are like 80% slower than a comparable AMD CPU.
BTW, calculator.s3.amazonaws.com quotes me $1119 per month for a single c5.9xlarge, so I'm not sure how you would reach $8/day when I see $37/day.
And you can reach $8/day using Spot or Reserved Instances. Not sure where you get $1119.
I think the point if the article is exactly that: Unless you have a couple of TB to process don't even bother. I remember a similar post in the same spirit that had a couple of GB in a Postgres database and ended like "Just do a simple query!" instead of a Hadoop cluster for simple map-reduce.