How do people get so much gold?

How do you guys farm your gold? I sometimes read that people have spent 2-3b tempering and the way they’re speaking is like they not Even broke yet 😅 Is it just regular gameplay and gold stacks up slowly overtime, or is it more to it?

Edit: Thanks for all the tips. Selling items seems to be the most common answer, and i've tried that now. 50B in the bank all of the sudden. I guess i'm good for now