the difference is all the current capex is going to durable, hard to get physical assets + things like PPAs. In your online shopping analogy, the hyperscalars are acting like Amazon in 1998
What destroyed hardware manufacturers after the first bubble burst was all the old but overpowered server hardware ending up in resale after bankruptcies. Hard to get hardware is a bad investment that is also potentially obsolete after new optimizations make the next generation much more efficient. The companies that think their individual optimizations are going to outpace industry wide optimization are delusional, historically speaking.