I'm probably bias because I only play phlog pyro now days but I'm gonna disagree
Airblast is a huge thing. You can easily stop a uber dead in its tracks with airblasting, you can airblast people off cliffs, you can reflect projectiles of all sorts, you can extinguish teammates and now gain health for it, you can airblast spam deadringer spies in corners until their cloak drains (same thing with spies using the icecicle), you can fuck up jumpy scouts with an airblast, you can airblast a heavy or enemy away to get some distance while fleeing which can be very helpful, and more
And you also get random crits which can cause some major hell
Phlog's forced crits and health refilling is all it has going for it