Which is better for video editing macbook air M1, mac mini M1, or Ipad pro M1 ?

Since they all have the same processors (the "step up model" of the MacBook Air has the identical M1 with 8 GPU cores) along with the 13" MacBook Pro, it all boils down to the need for portability.

If you don't have any need for portability, the Mini or the new M1 iMac would be the choice to make. There is no sense paying a premium price for portability if you do not need it.

If you do need some amount of portability, the M1 MacBooks would be a better choice in my opinion because expansion is much easier and you are not shackled by all the limitations of the iPadOS especially in choice of apps. The M1 MacBook Pro may be a better choice because it has a fan if you are doing CPU/GPU tasks for an extended period of time.

In general, a desktop is better-suited for the purpose. The mini in this case, even though both the pro and book are M1-equipped. Main reasons: better cooling & no dependence on battery.

Well, non of them if you do stuff like 6k, 8k raw and you plan to post this videos to youtube. 1080p or 4k shoul be enough for this kind of videos. If you plan to edit videos in 1080p or 4k then macbook pro or mac mini will be good for you but you must concider buying at leaad st 27'' monitor on wich you edit because macbook pro-s 13'' is to small for edit. I edit weddings and some comertial marketing stuff and it's just ok and I dont care if m1 rendering video takes 30sec or 2 minutes longer then on other macs with 12 cores and dedicated graphics or two of them that cost like a small car (lots of crap videos on youtube).

Just go and buy any of them, but 16Gb of ram memory is a MUST!