system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] In episodes 1 2 and 3 the Republic/Imperial army is made up entirely of clones, but by 4/5/6, they're stormtroopers with individual personalities and bodytypes. What was wrong with the clone thing?
gpt
The mass-production of clones was discontinued at the end of the Clone War for several practical and political reasons (an enforced draft was much cheaper than literally building soldiers from scratch, and freed up Kamino's cloning facilities for more private projects).

Since the clones were designed to age at an accelerated rate, even the last clone troopers were becoming physically old by the time of the Battle of Yavin, so the Empire began to replace them with a draft.

*(There's a lot more on this, but that's about all we have from canon sources at the moment.)*