Since I'm one of those not so lazy types, AIO's have one huge advantage over aircoolers. Control. There's Cam, iCue, Corsair Link, built in mode control, Evga flow control etc all built specifically to monitor temps, customize and control fan curves, pump speeds, noise etc.
The old brick of an aircooler gets 3 choices. Bios, motherboard software and SpeedFan. Bios is a joke, you set the finishing duty/temp and thats all you get. Motherboard software can be better but honestly mine has only 2 adjustable points, so start - end. SpeedFan is a royal pain to setup correctly, there's no automatic anything until you say so and everything is run through addresses. Get the wrong address and your exhaust fans respond to cpu and cpu fan spins 20% forever. That's if you can get it to work right in Win10.
At least with aio software it's graphically customizable, self starting, set-it-and-forget-it.
You can also put an aio in any case that mounts 120mm/140mm/240mm/280mm mounts. Good luck with putting a $30 CM hyper212 evo in even half of the available cases out now, same goes for the similar hight NH-D15S at 160mm.
And let's not go into ram clearance issues on anything, even my Cryorig R1 Ultimate has serious ram clearance issues, covers both the 1+2 slots.
Most cases come stock with 2x case fans. Aircoolers almost require purchase of additional case fans to meet airflow needs. Aios double as case fans, eliminating that extra expense.
AIO's have advantages over air, and Aircoolers have advantages over liquid. They both do the same job in respective ranges, just in slightly different ways. It really just boils down to preference and aesthetics once past case physical limitations.