"That a business that would use Ruby in 2009 would use Go for the exact same thing in 2021."

Companies are building the same sorts of solutions in Go today that they built in Ruby in 2009. Loads of web applications are being built in Go.

Like I said, around 2010 even payment (e.g. the fundamental opposite of where a dynamic type system makes any sense) systems were being built in Ruby because it was the hotness. Though no one has wed themselves to an ephemeral choice quite like Shopify has, and most other examples from that era now have a rich, diverse technology platform.

"Need to prototype a CRUD website super quickly? Ruby, Python, PHP, JS."

That's like the first 0.05% of a product. Like building your GUI in Adobe XD.