You don’t even need higher level tasks like that: take something as seemingly simple as processing text. That used to be 8 byte operations, display was looking up a bitmap and copying it into a buffer, but once programmers accepted that humans use more than ASCII and want nice displays that started to involve context sensitive decoding and display, processing vectors, subpixel rendering, etc. All great improvements but most of them require more CPU/RAM than a 30 year old computer had, too.

Only if one doesn't look into the right place.

Mikroelektronika has Basic and Pascal compilers, in addition to C, for all those slow CPUs that are market relevant.

https://www.mikroe.com/compilers

And they aren't the only ones still alive.

> Firefox and Chrome are written in C++;

Firefox is on a course to remove C++ from safety critical areas and replace those with Rust.

Edit: to be clear this is based on the blog posts I’ve read from Mozilla about the introduction of Rust in different areas of Firefox. I know nothing of firm plans.

'On a course' implies that there's some sort of definite plan and resources delegated to the task. Which isn't true of Firefox and Rust, as far as I know.

While it may not be an explicit goal, everything I’ve read implies that, for example the heading in this wiki on oxidization: https://wiki.mozilla.org/Oxidation

> Moving forward, the goal of Oxidation is to make it easier and more pleasant to use Rust in Firefox, and correspondingly to increase the amount of Rust code in Firefox.

And then there is the Rust page on Mozilla’s site:

> Mozilla also utilizes Rust in many of its core initiatives including Servo and key parts of Firefox.

https://research.mozilla.org/rust/

Where “key parts” is a link to the project quantum announcement: https://medium.com/mozilla-tech/a-quantum-leap-for-the-web-a...

> Initially, Quantum will share a couple of components with Servo, but as the projects evolve we will experiment with adopting even more.

There is, however, no expectation or any real plan that C++ will be gone from Firefox. There's a huge amount of code, and there's a cost to rewriting it.

I only claimed “safety critical areas”... the other millions of lines and OS interop for UI, etc., will most likely not change for a long time.