It's stupid how much they are pouring into hardware that might be vastly obsolete. By the time AI becomes truly intelligent, there may be specialized chips that are efficient at running models that blow GPUs out of the water.
Look at how it happened to bitcoin mining. Nobody serious is using a GPU to mine when ASIC is available.
However, I don't see all this hardware hitting the second hand market once a better solution is found. I'm sure they will keep trying to make compute hard to get for the average person so they can rent out their servers for a crazy price.