This is a good question for several reasons.
We at home have laptops that can't be upgraded. What should we do with them as 'enhanced' software strains their hardware? Also, one person maintains them all. A company would have servers & an administrator.
I've a 'dumpster' tower. Why not upgrade only it? I'd like to place between the aging laptops, internet, peripherals, printer queues, mail boxes, & constantly-running security programs of all kinds. This would allow our old laptops to continue to run satisfactorily.
I'd also like to install a free voice mail program there and use it as a 'filtering' voice answering machine, eliminating illegal phone spam that fills ours. Debian Linux can read & write to most any filesystem and supports 'green' features.
Now, we haven't many laptops, and we don't need blazing speeds. Extending the life of laptops and freeing my time saves money as well.