Key words are building towards a chip and higher ceiling.
The jazz don’t have a great chance, but they have a chance at a championship this year. The suns do not. However, with Conley and Bog getting older, that window will shrink as the suns window increases.
Now Mitchell/Gobert is better moving forward than Booker/Ayton at the moment...and you probably can replace Conley/Bog...at least with players similar to Oubre/Bridges.
The big question here is Ayton. Can he reach his ceiling, because his ceiling is higher than Rudy and in that case I can see the rationale for picking the suns.
Personally, I don’t think Ayton will ever get to the level of the elite centers(KAT/Embiid/Jokic) He feels more like a Drummond/Vucevic level player. So I’d go with the Jazz core being most likely to win a championship. Think the suns will need to add another blue chipper to Booker to get in the discussion.