On-prem servers don't run themselves: there's hardware maintenance, depreciation, security, networking, license renewals etc etc.
The typical customer I see who's moving from on-prem to cloud has a clear trigger/deadline in the form of hardware reaching EOL or licenses being up for renewal, and these aren't going away with COVID.
On prem equipment can be depreciated, and you can drag out the useful life of the equipment you own if necessary. Cloud opex evaporates each month, never to be seen again.
CTOs/CIOs call the shots when times are good, CFOs when times get lean.
The typical customer I see who's moving from on-prem to cloud has a clear trigger/deadline in the form of hardware reaching EOL or licenses being up for renewal, and these aren't going away with COVID.