> let the developers choose

Absolutely not. Developers making choices about stuff like that is asking for troubles. I'm an SRE - and this is how production issues start, because some dev decided that somehow, in production, something like this should not be there, until problems pop up, but then it's too late.

For us it's simple, the moment it hits the CI/CD pipeline, it's a production build, even if it happens just end up on some test or staging environment. If you possibly need it there, you need it on production. Our way of working means that the exact same build artifact should be promotable to production.

There is a big difference between choose and do.

I don't understand what you mean; can you elaborate?

Not a parent commenter but I interpreted that as: given choice between alternatives A (fast and good enough) and B (more complex and much better) you would want to choose B but end up doing A for various reasons (lack of time, unclear ROI etc)

Sure, but the toolchain designers can (relatively easily) offer both, so that people who really do have the resources and/or need to do B can do so.

Are we still talking about a language that protects its users from the ability to write generics?

That’s a language feature; we’re talking about build flags. IMO, adding a build flag wouldn’t meaningfully change how simple the language is to learn and use, whereas there is at least a credible argument that generics would.