Why do you flat preflop in the AA hand?

You end up going 4-way to the flop with a vulnerable one-pair hand. If you get much action and a big pot happens after this, you're often going to lose.

People can't always have anything to pay you off with.

Your 60-70% pot sized cbets are fine as a broad guideline, but your bet sizing should vary based on board texture and opponent - because you're varying your bets based on these things (which everyone at the table knows) rather than your hole cards (which only you know) this variation doesn't give away your hand strength.

If you're winning small pots and losing big ones, if that happens over a statistically significant sample of a whole lot of hands, then it may be that you are not getting away from marginal hands often enough and you're allowing big pots to happen when you are likely behind. It also may mean you're playing your own big hands too slow, not building big enough pots with them because you're afraid to scare everyone else off - although it sucks when people can't pay you off, you just have to accept that will happen most of the time - generally, it's best to just bet anyway and rely on peoples tendency to call too much.