From my experience in the industry, if the average backend dev went to work in that industry, the average level of competence would go up (compare the average salary, for one thing). The processes are all about making it hard to fuck up really badly, they're very much not going to weed out 'careless' devs, just limit the damage they can do.

I don't think "careless" is a permanent, intrinsic attribute of a developer. It's something they learn to be, and it can be unlearned.

We respond to incentives. If a developer's only incentive is "we reward shipping as fast as possible" then they will carelessly ship slop as fast as they can type it. If that incentive is removed, they can learn a better way...