I'm not sure about them being garbage but I do believe very strongly that existing SaaS software is way way wayyyy overpriced. So there is an opportunity to build a simple, low price software that does less but just works.
Maybe you will end up getting like 25% of their customers but if you play it well that is going to be worth still a lot.
If you're competing on price, you're usually competing for the worst customers. Good for them, but not so nice for you.
This is true. Also, if you are only competing on price, it is easy for a competitor to undercut you.