Think about that.
There is no excuse for how slow software is today. None.
Many parts of Windows 95 were faster in wall clock time in 1995 on the hardware of 1995 than today's Windows 10 is on the hardware of today. Yes, today's software does more, but THAT MUCH more? Are you sure?
The hardware we have is very fast. Software developers have been relying on hardware upgrades for performance improvements for far too long, and now few software developers know how fast things can be, if they just try just a tiny little bit.
Also, OOP teaches developers how to think about software in ways that are exactly opposite to how computers actually do work efficiently. Object oriented programming is just inherently slower because it encourages developers to think of things one at a time. Computers like to do things in batches.
More people need to think about performance, because clock speeds aren't going up like they used to, and we still don't know how to write software that spreads across a lot of cores very well. The free ride that hardware upgrades provided us is quickly coming to an end.
tl:dr; everyone needs to learn about how processor caches work, especially the 24-year old JS devs who think they already know everything.
Modern software sucks.