Manufacturing. The cost to a factory if the internet is down is too great. Each facility has its own highly redundant virtualization infrastructure hosting 50 to 100 VMs.
I was in manufacturing IT before moving to big tech. Our big campuses in the US & Europe had 40-80mbps internet circuits. The remote facilities in developing countries often only had 10mbps MPLS connections to a regional hub. To be 100% honest, we had 10x the outages caused by crappy local infrastructure than anything having to do with a SaaS service or IaaS/PaaS provider. Seriously, things like bad storms, a snake (cobra!) sneaking into the server room and frying itself and a machine it was snuggling against, utility workers accidentally severing cables, generators failing during power outages, labor strikes, and so much more. Moving to the cloud -- or even just hosting everything centrally -- was much more stable than maintaining a fleet of distributed machines.
Manufacturing Here. This is also the Case with us. Also the cost to run our on-prem in the cloud would be almost 10x what we pay right now. Such an insane amount of CAD Data, there is 0% chance we can get an internet connection that comes close to what on-prem can handle for our massive cad data.
Manufacturing is the one place I still use on-prem, mostly because I work in a field that has compliance reasons for doing so and the, 'internets out, we can't print' problem.
