GPUs have a five year lifespan before they become obsolete and start experiencing reliability issues. We're already 1-2 years into that five year lifespan.
The payback time for a GPU running 24/7 inference is ridiculously short though. As little as 6 months according to some calculations. Most of that 5 year lifespan it will be earning well in excess of its replacement cost.
bean counters are better at establishing asset value than you are, and as I mentioned elsewhere, income streams are assets also