Just this spring we had to port CI4 for a game service in France that ran on such low-end hardware, it didn’t have enough memory to fit all the graphics in (we had to use half-size versions). A lot of phones have very limited free storage space and having a bigger footprint reduces your install base, which reduces your users, which reduces your income, which reduces your meals 
Perhaps it’s true for multi-million dollar productions, but nothing is “easy” and nothing comes for free when you’re essentially running a one-man show.