Exactly. In a normal handoff, the offense has 9 guys to block 11 defenders. If you go direct snap, you now have 10 guys to block 11 defenders. Now you can argue that taking away the threat of a pass is more detrimental than the benefit of an additional blocker, but if they’re selling out for the run anyway it doesn’t really matter.Extra blocker if the QB can lead.
Same reason the read option has become so popular. By having the QB be a threat to run, he takes the backside end out of the play and you now have 9 guys to block 10 defenders instead of 11.