It may not be slower, but it's definitely less efficient.
You can really see the loss of efficiency in modern software by using the same program/application on a modern machine vs a 10 or 15 year old machine. I have a couple of older laptops (2001 era Dell Latitude CPx with a PIII 500MHz, 2011 Lenovo Ideapad netbook with the Atom N450 1.6GHz) that I will occasionally play around with. I've found that most of what the article author said applies; textual interfaces with minimal or no mouse usage runs perfectly well on either of those old beasts, even with code written in 2020 and optimized for modern hardware. The "suckless" suite of tools in particular (dwm, st, surf, etc.) make those otherwise unusable machines into something approaching modern workstation utility. You don't want to even try to run any modern graphically rich software on those devices as you'll be frustrated immediately, and it will be clear just how bloated and unnecessary a lot of modern design has become.
I feel as long as we keep advancing in raw computing power, the software can be allowed to grow and make use of the extra power, but we will eventually reach a standoff where the hardware stops advancing and at that point we will need to focus on reducing, not increasing, software bloat if we wish to maintain efficiency.
Actually it does albeit indirectly, because you are not running a single application on a modern computer. When they all start starving for memory they get slower.
You can really see the loss of efficiency in modern software by using the same program/application on a modern machine vs a 10 or 15 year old machine. I have a couple of older laptops (2001 era Dell Latitude CPx with a PIII 500MHz, 2011 Lenovo Ideapad netbook with the Atom N450 1.6GHz) that I will occasionally play around with. I've found that most of what the article author said applies; textual interfaces with minimal or no mouse usage runs perfectly well on either of those old beasts, even with code written in 2020 and optimized for modern hardware. The "suckless" suite of tools in particular (dwm, st, surf, etc.) make those otherwise unusable machines into something approaching modern workstation utility. You don't want to even try to run any modern graphically rich software on those devices as you'll be frustrated immediately, and it will be clear just how bloated and unnecessary a lot of modern design has become.
I feel as long as we keep advancing in raw computing power, the software can be allowed to grow and make use of the extra power, but we will eventually reach a standoff where the hardware stops advancing and at that point we will need to focus on reducing, not increasing, software bloat if we wish to maintain efficiency.