Then you catch it quite late with current techniques. Hopefully in the near future it will be super accurate and something you can just do at home.

Those aren't highly accurate. I think they just detect blood in the stool, which could come from one of several causes including simple haemorrhoids. If you pop positive on your ColoGuard you're expected to come in for a colonoscopy.

Those tests have a fairly high false positive rates. Hemorrhoids for example can cause a false positive, and are pretty common in people over 50 in the US.

Once you get a positive, even a false positive, health providers tend to try to switch you from an annual poop in a box test to whatever the normal colonoscopy schedule is at your age (e.g., every 10 years unless your previous colonoscopy found something that calls for a shorter interval to the next one).

Poop in a box detects pretty far along cancer - bleeding into the gut. Colonoscopy finds it a lot sooner.