The only other time I can imagine is if a company isn't going to exist in six months, such as movie productions, or companies that have so little going on that they don't need more than a $10 a month plan.
Otherwise, on premises or colocation are invariably cheaper when there's any kind of real usage.
The other company was software for automotive companies and marketing, only US based so traffic was non existent from midnight to 5:00 am, and some companies would need to ramp up for events like NFL games when they’d advertise.
That is true, if peak load is much much higher than mean load.
For most companies, that's not the case.
On the cloud you are overpaying for cpu, network and storage by a very wide margin. That makes sense if your peak load is, say, 100x your mean load (and you have sufficienly smart autoscaling to optimize for this).
But for most companies there is not such huge multiplier from mean usage to peak usage. So those are better off with owning hardware.
I worked at a medium sized place where we had plans in place to handle the workload for our entire market on-prem (if we were ever to capture that market).
We realized that horizontal scalability wasn't important to us because we had enough of the market to know that the other half of the market could be supported on our existing solution.