No it's not. You would objectively be better off in Java or Go than Ruby once you reach scale. Java and Go can truly utilize multi-core threading, and have superior garbage collectors. This matters a lot for latency requirements

You edited your response. How many of those companies are profitable?

I edited my response from "Without more data, your original statement that "you'd be better off" is just as subjective" to the more fully fleshed out comment you see now while I was looking for a link for my sources.

You, on the other hand, are moving the goalposts.

I'm not moving goal posts. I never said you could not be successful with ruby. All I'm saying is that once you hit scale, you would have an easier time cutting costs in a language that could better utilize less infrastructure and thus lowering your operating costs.

For overwhelming majority of startups hardware is a tiny fraction of their operating costs.

Not to mention that a lot of the hardware costs are language-agnostic: database servers, disk volume.

Why do people keep misreading what I'm saying. The argument is specifically for WHEN YOU REACH SCALE

To most people "reaching scale" means either revenue number or number of customers (word "when" implies that).

You can easily reach "scale" (earn millions of dollars, serve millions of customers) while still running on 2-4 web servers.

Name one company that runs 4 servers of ruby and earns millions per year

Given that very few companies in the world make their infrastructure public and I never worked in a Ruby shop, I can't.

But I've done it with Python and I can't see why Ruby would be any different.

A company makes millions of dollars through 4 servers running python?

Yes, 2-4 web servers. And it's not like they are using most expensive configuration, just 4 vCPU per node. CPU utilization is below 20%, so it could even run on a single node, but that's not good for availability.

Why is that so surprising? Nobody sane does anything CPU-intensive in their webapps.

Probably because your original comment doesn't say anything about scale and instead says specifically "you'd be better off," which implies "better off from the start." I'm not saying that's what you said, but that's what it reads as.

I guess "successful startup" doesn't equate to "scale" ?

No, it doesn't. A successful startup can have a few large customers and millions of dollars in revenue.