CBM just tried to sell the old hardware without investment
That isn't entirely true. They were investing, just not in the right things.
AAA was started in 1988 and dragged on and on. It's been said that AAA didn't get enough investment, but IMO it shouldn't have gotten any investment at all.
AGA was done in a year by a couple of engineers who decided that AAA was going nowhere and that something else needed to be done.
If AGA had been started in 1988 then commodores future would be different.