Questions · Evaluate

Can I leave out availability to avoid showing low stock?

It is a reasonable worry and it does not apply here. The schema.org values are deliberately coarse: InStock and OutOfStock say nothing about quantity, so stating availability publishes no inventory level and tells a competitor nothing they could not learn by adding the item to a basket. What omitting it does is remove you from consideration, because an agent that cannot tell whether something is buyable will usually recommend one that says so.

Why it happens

Availability is the field that decides whether a recommendation is safe. An agent that recommends a sold out item wastes the shopper trip it was asked to prevent, so agents weight unknown availability towards not recommending.

This bites hardest on stores where sold out variants stay listed, which is most stores. The catalogue looks large and healthy to a person browsing it, and reads to an agent as a set of products whose purchasability is unknown.

Run a free scan and find out which of these your store actually hits.