Because that's not what happened.
The existing garage was falling apart. It needed to be replaced. As part of the replacement, a large tower was proposed on one side, and a theater on the other, which resulted in the garage size being increased.
This garage was also like 90% complete pre-covid, so it's not like they were choosing between the garage and assisting businesses hurt by the pandemic. Not that it would necessarily be a wise decision in this case anyway. We don't know when or even if downtown will ever return to the prior traffic patterns.