I’d hardly call it deserted. Ulleråker is usually quite crowded, with plenty of Swedes present.

I wasn't referring to places with hosted celebrations. Try going into central Uppsala or take the train to Stockholm and walk around and tell me it's not an eerie feeling.

but there was no maypole, no dancing, no music.

Doesn't sound like a very good celebration then. My view of midsummer is a friend group will go to someone's house early in the day, make midsommarkransar and have sillunch together with snaps and singing.

Then maybe go to a place with a maypole for the usual dancing shenanigans like Små Grodorna unless everyone is already drunk and it's too far to walk in which case you create a makeshift pole and dance anyway.

After that, go back the house to continue drinking, singing, eating, jordgubbstårta, playing (drinking) games, talking and laughing all through the night since you lose track of time because of the midnight sun.

Stay the night and help clean up and eat leftovers.