not true,
If you want to go by QB purism, stricting rating them by their passing performance, then Allen (and Jackson and a few others) are way down there. Buffalo would be -3 wins at this point this season (and other seasons) without the monkeyballing.
Burrow has a bottom-five offensive line in pass protection in the NFL, he's a pocket passer and yet with his arm alone he's put his team in position to win all but one, maybe two games. It's not his fault his horrid general management refuses to invest resources in offensive line and they've neglected the defense badly as well, too. He's basically 2011, 2012, 2013 Tony Romo but better.
Allen has a top 3 offensive line in the NFL and you could make the case for #1 overall, I believe PFF backs that up as well. Their run game is amazing, Allen gets infinite time to throw every dropback, and their defense has been very much elite up until the last 2 weeks when they've regressed pretty badly. The Chiefs meanwhile have arguably the worst OT situation in the league and it's been that way since the year they lost the super bowl to Tampa Tom Brady's Bucs. Their interior is fine so they can move the ball with inside runs but Mahomes has been running for his life all season long, as has Burrow, while Allen has been baking cakes back there in the most pristine drop back pockets you'll see this side of the early-mid 1990s Cowboys.
If you want to count both passing and monkeyballing, then you have to put Jackson over Allen even for this season. Jackson's stats are insane, (both his TD/INT ratio are 2013 Nick Foles-level insanely good and he's the best running QB in the league when he's healthy and it isn't close) even if the defense has regressed and his team has an unusually high number of losses this year.