> C++ is very good, when you need to integrate a lot of 'low-level' libraries ... like for instance, browsers do.
That's sorta funny that you use that example, since rust is a Mozilla project, and they've already moved some parts of Firefox over to rust, and plan to move more in the future. Clearly this is not an impediment; reasonable C/C++ interop was a must-have for rust's design.
> If you are already a experienced C++ dev, compared to modern C++, Rust has very little to offer.
That's a weird argument to make. Essentially you're arguing that you should never learn any new languages once you have proficiency in something similar? That would seem to be a bit short sighted.
> ... at least not for people with large codebases already in C++.
Sure. No one's saying "throw out all your C++ code and rewrite everything in rust" (and if anyone is, they can be safely ignored). But that doesn't preclude taking a look at some parts of your code that might benefit from being written in a safer language, or rewriting small tools in rust, or considering it for new projects.
> When you are younger, programming languages look like that secret ingredient that will turn whatever you do into a magical tool.. But experience tells you that nothing beats hard work or that you should understand the strenght and weakness of each language, and know when and how to use it.
No one's saying languages are magic, just that, by some metrics, some are objectively better. This might be an odd example, but I did Java for many years before switching to Scala a couple years ago. In the past few months I've had to go back to Java, and it's been frustrating that it's so easy to write certain classes of bugs that I just never see or write in Scala. Does that make Scala some magical tool that fixes all my problems and means I don't have to do any work? No, of course not. But it is objectively better than Java by some metrics (and sadly, worse by others).
> modern C++ is already secure enough
That's a pretty bold claim, and I'm certain it's not true. You might have a different idea of what "enough" is than I do, though. I'd believe that the "default" state-of-the-art C++ use is more secure than it was 10 years ago, but that doesn't mean that a language like rust can't offer superior safety guarantees.
And there's something to be said about encouraging safer practices through language features and convention. If you can make certain kinds of errors in C++ programs (I don't see pointer arithmetic going away any time soon, or people always using vectors and the like and never raw arrays), then you (or someone else) will, regardless if there are safer ways that help you avoid those kinds of errors. Given a language with a huge surface area like C++, and disagreements on what are the "safe" parts to use, it's inevitable.
> If you throw a language like Swift into the equation.. particularly i think they(C++ and Swift) form a lovely and unbeatable couple.
Despite Swift's open source status, I really don't see it making any meaningful foothold outside macOS/iOS.
I don't have a horse in this race. I abandoned C++ years ago, and I've only started learning rust a few weeks ago. I like it, but I have a lot to learn, and I've already found some rough spots that aren't so great. No tool is perfect.