With an Instant Pot, an induction burner, and a toaster oven you can make anything that would require a normal kitchen, just in smaller portions (as in, you aren't cooking a whole turkey or a giant casserole).
Otherwise, if you already have a convection oven and don't mind waiting a bit longer, I don't see a good reason for purchasing an air fryer (other than the aforementioned advantage).
It really does work better than my conventional oven.
Edit: oh yeah, add an air fryer and bread machine. And kettle obvs. Preheats water for a pasta pot faster than the stove. Immersion >> conduction heating.
The amount spent on a range buys a lot of gadgets. Not even wiring one up saves a circuit and dedicated run.
I couldn’t live without a dishwasher though…
When I empty it, I’ll let anything that needs another run in for the next run.
Don’t need to run it every night.