Efficient role separation?

When devs would only write code and never click anything around in the system how can they implement anything good?

I don't believe in "efficient role separation" that is 100%. Devs still need to click the system around and still need to attend meetings that give business context. The same for QA, they should understand basic exceptions and know where to find logs to make good reports and not just make screenshot and say "not passed" and drop all troubleshooting on the devs or ops.

Best outcomes I see are when you have multidisciplinary team where team members work together. Of course you have Dev or QA specialists but you have to have people who don't throw stuff over the wall and are focusing on delivering togheter.