This is not at all unusual. These days, two years is probably the fastest you can reasonably expect --a year for the illustrator to work, a few months for production, and nine months (yes!) to get advance promotion and sales efforts lined up (this includes the lead time required by B&N and Amazon). If the illustrator has any other projects already committed, you add more time, which as others have said can be years. The pandemic may have added a month or two to this, but it's not a significant factor.