The pandemic, the Black Lives Matter movement and the larger political dysfunction of the 2020 election cycle almost certainly made director Ian Denyer’s three-hour documentary, “Inside the Met,” a stronger, more substantial film. The documentary is framed by crisis, opening just before the pandemic hits and closing with the election of Joe Biden in November 2020. It feels like a bit of a palimpsest, with the residue of a simpler, more purely hagiographic film poking through now and then, despite an admirable focus on how the events of 2020 challenged the institution financially, culturally and intellectually. The opening of each of the three hour-long episodes reminds you of the Met’s size and scope — the largest museum in the Americas, five stories tall, four blocks long! — but this PBS-style breathless wonder soon gives way to substance.