My problem with this is it sort of implicitly assumes that languages are the unit of progress. It's unlikely that we will get progress solely by coming up with

My problem with this is it sort of implicitly assumes that languages are the unit of progress. It's unlikely that we will get progress solely by coming up with better languages, it's more like different people invent different tools to suit different problems. In the explosion, we are more likely to find what we need. I don't think I've ever used just one language for a project. The progress at least personally is that there are now so many resources to use a bunch of different languages to knit together a solution that a lot more can get done. You can write your low latency code in a variety of languages, and ship the data via a web server to a browser or a mobile app. For every part you have several choices of tech to use, and they're realistic choices with lots of help online. Almost everything is available for free, so you can try all sorts of libs without committing to one. There's no longer a need to sit down with a textbook and learn a bunch of stuff before starting, you can just jump in with a brief tutorial and explore the language or lib as you discover them. The plethora of choices also teaches you a lot about languages in general, because you see so many that you can start to make generalizations.