Yes, that's kind of the same point. But Conway's Game of Life is extremely easy to study in silico and has much simpler rules than chemistry.

Correct. And you don't write it just once. I have written it many times, first literally as cells in a 2D array. I wrote it in assembly language too. I later wrote sparse list versions (since most cells are usually empty). I have written it using bit parallelism (generating 8x4 "bricks" of cells) with lookup tables, with lookup tables and with sparse representations. I wrote it as a Java applet for a now ancient web page (1995). I never implemented HashLife though.

Today https://sourceforge.net/projects/golly/ is fast and does about as much as most people need.