I think a pandemic absolutely plays into low attendance numbers even after the increased capacity. People were still reluctant to go be in crowds. Plus, they had fewer dollars to spend on entertainment as a result of possibly reduced wages, lost jobs, and any of a number of things that happened during the pandemic. Higher cost of goods limits the entertainment spending. It's impossible to look at the low attendance throughout baseball and at movie theaters and not see a trend of people spending less to go out in crowds that stems from the pandemic.
There were other factors in play:
-- When the Cardinals played their best, families were returning to schools, and for some that was school in person for the first time since March 2020. So that's a factor.
-- The Cardinals spent most of the season being less than captivating as a team. They didn't have the charisma or buzz of a team that demanded to be seen in person. They didn't capture the imagination of the fan base, and you could argue ran out of games by the time they did.