Hardware Aging & Refresh Cycles
Unfortunately, IT infrastructure and hardware doesn’t last forever, and an often overlooked fact is that the older the hardware, the highest the maintenance costs. Not only is it increasingly difficult to source parts, but the vendor will increase support costs as their costs increase over time. At some point, it becomes uneconomic for a vendor to continue to support and so the hardware becomes deprecated.
Even before the vendor drops all support, the increasing support costs can outweigh the cost of a migration, and so a common driver to move to cloud is where the on-premises infrastructure has already become too costly to continue to run.
For some companies (especially in heavily regulated industry sectors) regulatory compliance can be lost when hardware or software goes out of support, and so this can force organizations to upgrade even when parts are available and the system is running very well.
There is a second important point to note is that if a hardware change is necessary, then the cost of moving the system to new hardware will be incurred whatever the destination - on-premises or to public cloud. It’s also very likely that an on-premises replacement will require significant capital expenditure for new hardware. In many cases, as a migration costs is _baked-in_to every option, then a public cloud destination will likely work out as the cheaper TCO option.