There’s no marginal tax impact of discarding it or not after 5 years - if it was still net useful to keep it powered, they would keep it. Depreciation doesn’t demand you dispose of or sell the item to see the tax benefit.

No but it tips the scales. If the new hardware is a little more efficient, but perhaps not so much so that you would necessarily replace it, the ability to appreciate the new stuff, but not the old stuff might tip your decision

"Depreciation doesn’t demand you dispose of or sell the item to see the tax benefit."

It does require to dispose the item if you are a government entity otherwise the budget for the new item isn't allocated.