Players who hack gems or unlock all heroes immediately miss:

A hacked kingdom is a silent kingdom. Your armies march, your gold piles glow, and your heroes never tire. And you are utterly, miserably bored.

Furthermore, the PC version (via Steam or GOG) allows for file editing without malicious APKs. You can edit the .sav files with a text editor to increase your stars. While still cheating, this granular approach allows you to customize the difficulty (e.g., giving yourself +10 stars to unlock the Necromancer early, but leaving gold vanilla).

While "hacking" is often associated with gaining unfair advantages, in the world of Kingdom Rush Frontiers

The purest, most dystopian form of hacking. This mod detects the start of a wave and immediately triggers the victory condition. You click “Start Wave,” and the level ends with five stars.