Interestingly, the Wirecutter recommends people just get a really good high end toaster oven[0] over an air fryer, since its just a convection mode cook.
[0]: https://www.nytimes.com/wirecutter/reviews/best-air-fryer-to...
[0]: https://www.nytimes.com/wirecutter/reviews/best-air-fryer-to...
Personally, I use a separate metal basket in my convection oven. But it's entirely possible that more convection would be better.
By comparison, the new breville I have does everything the old one did plus air frying, and the difference is distinct - I tried making fries in the convection baking mode on the old one and the result was noticeably worse than what I get from the new one in air fry mode. Noise and heat output approaches annoying levels with either air fryer, so I'm pretty confident the experience I get is close or the same as the purpose-build one. And the ability to space things out more gives better results, at least for my purposes. (I'll note that 95% of my air fryer use is for fries.)
You can also steam-slow-cook meat and get juicy tender chicken.