Author of ripgrep here.
It's worth pointing out that while exa uses the term "modern" to describe itself, fd and bat currently do not. And I can say with certainty that ripgrep never used the word "modern" to describe itself. I didn't like that strategy even back in 2016 personally, and specifically tried to avoid it.
With that said, to try to argue the point more directly, I do think this is a somewhat shallow concern. It's unclear to me how much predictive power using the word "modern" to describe a piece of software is. I don't like it because it's vague and its meaning is somewhat of a moving target. But broadly speaking, it does convey some things: non-POSIX, does bolder things in the name of user experience and maybe some other stuff. It's a pithy signal. But I'm not sure it has much to do with "staying power."
Presumably coreutils has staying power because there is purportedly a specification covering their behavior (kinda, not really, lol) and organizations responsible for maintaining them. So if you want staying power, stick with the stuff that has a high bus factor and is well funded. That's totally fine.
