You don't need the entire executable file in cache in order to run the program.
For comparison, a C++ wxWidgets 3.0 application isn't going to be much smaller than 10MB in release mode if you statically link it. Much as I hate to admit it, 10MB just isn't that big in an age of terabyte SSDs and systems with 32GB of RAM.
Not that the majority of users have that. Even eschewing those outside of wealthy countries, most users are on mobile devices (laptops, tablets, cell phones). Of those who have desktop PCs, very few have terabyte SSDs and even fewer have 32gb of RAM. For most people, RAM is probably somewhere between 4-8GB.
I don't think it's healthy to think of that 4GB module as "RAM".
It's connected to your CPU by a serial communications interface so access is not uniform or timely, and if the CPU needs any of it, it stops what it's doing while it waits.
The "cache ram" (L1 and to a lesser extent L2) actually acts like the RAM that we learn about in Knuth, so that when we discuss algorithms in terms of memory/time costs, this is the number we should be thinking about. Algorithms that are performant on disk/drum are modern solutions for what you're calling "RAM".
For comparison, a C++ wxWidgets 3.0 application isn't going to be much smaller than 10MB in release mode if you statically link it. Much as I hate to admit it, 10MB just isn't that big in an age of terabyte SSDs and systems with 32GB of RAM.