It's the opposite. The more consistent your workload the more practical and cost-effective it is to go on-prem.

Cloud excels for bursty or unpredictable workloads where quickly scaling up and down can save you money.

Other benefits: easy access to reliable infrastructure and latest hardware which you can swap as you please. There are cases where it makes sense to navigate away from the big players (like dropbox going from aws to on-prem), but again you make this move when you want to optimize costs and are not worried about the trade-offs.