I recognize that not everyone designing a new language is doing it to compete with other languages in the same problem/application-domain and achieve (and retain over time) similar adoption levels. But for those who are, what overarching, high-level design strategies matter and why? How do those design strategies help achieve that goal?
Some additional qualification / scope narrowing of the question:
I realize that the words "long-term adoption" and "widespread adoption" are pretty murky/ambiguous. More concrete descriptions might might be "adoption growing and lasting over the next 20+ years", and "adoption at a similar scale to other widely-adopted languages occupying a similar problem-domain(s)".
This is a question about overarching design strategies for the stated goal- not about things like the language design team having enough funding, having good teamwork, quality of "product", rollout, or investment in marketing. It's about what the language has to do or be to have a place in the ecosystem it wants to enter- not about what the people designing it have to do on top of designing it.
This question applies equally to new languages (and their tooling ecosystems) designed to compete with other ones in a similar problem/application-domain, or new languages designed to evolve such existing languages in ways that the designers of those languages choose not to.
Please give concrete examples from languages who have used the design strategies you name and have went on to achieve the stated goal. I.e. back up your claims with evidence. This question intentionally doesn't constrain the sought examples to any one specific language. What I'm seeking here is a bigger-picture view.
Another title for this question might have been (sorry for any leading of the question here): "What overarching design strategies have contributed to the adoption of languages such as C++, TypeScript, Kotlin, and others?" (because I think they're mention-worthy examples of languages that have (to varying but significant degrees) succeeded in attaining those goals in those circumstances)
