Wish can't duplicate 9th-level spells, but it can create magic items. Is there anything stopping a wizard from just Wishing for a 9th-level arcane spell scroll?
Nothing stops you from doing that, but it has increased costs
A scroll is a magic item, and Wish can indeed create it, even if it is of a spell that Wish would not normally be able to replicate.
However, there are some drawbacks to creating a scroll rather than duplicating a spell.
When a Wish creates or improves a magic item, you must pay twice the normal XP cost for crafting or improving the item, plus an additional 5,000 XP.
9th level spell scrolls have a base cost of 4050, making the normal XP cost for crafting them 162, which Wish doubles to 324. While this isn't bad on its own, if the spell had an XP cost, the Wish caster pays double that XP cost, and if the spell had an expensive material component cost, the caster pays 2 XP per 25GP in value of the material component.
Wish has a casting time of 1 standard action, regardless of the spell being duplicated. If Wish creates a scroll, it takes a standard action to create the scroll, followed by the spell's normal casting time to read the scroll.
A wizard can use Wish to duplicate a spell of their prohibited school (as long as it's 7th level or lower), but would not be able to use a scroll of the same spell. Similarly, while a Wizard can Wish for a scroll of True Resurrection (spending 7,324 EXP), the wizard cannot use the created scroll without help from a cleric.
The XP cost and the availability of better options
Wish can create magic items regardless of their price, but you pay 2/25ths that price in XP (twice the normal cost) which, for a 9th level scroll with no material component or XP cost, is an extra 306 XP on top of the 5,000 XP base cost. You could instead buy the same scroll for 3825 gp. No one who is considering casting wish as a cheap source of Meteor Swarm scrolls values 3825 gp more than 5306 XP.
If you are instead comparing wishing for scrolls with casting a 9th level spell directly, Wish takes an extra turn and you might not be able to use the scroll on your next turn (for example because it has been stolen or sundered). You also might need a UMD check, depending on the exact character and spell.