You're missing two key points to the cost benefit analysis. 1. Modern GPUs are remarkable at holding value. 3080s are selling on ebay at over half the launch

You're missing two key points to the cost benefit analysis. 1. Modern GPUs are remarkable at holding value. 3080s are selling on ebay at over half the launch MSRP. 2. You'll get better performance locally. People buy 4080s because they want the best.