You can’t back stab anything larger than 14 gauge. The holes are too small for anything bigger. You can back-wire, which is entirely different.
To be clear, back stabbed connections don’t use screws. They use spring loaded prongs which have a tendency to have poor connectivity and come lose. IMHO you should get rid of 100% of those from your home.
Back wired connections also use a straight in approach but the wire is clamped down by the force of the screw, and is held by two solid metal plates on either side. It IS a little more susceptible to losing it’s grip than wrap-around wiring, but a lot better than back stabbing.