That said, I'm in the US and not well equipped to speak to their responses, having not experienced them first hand.
Maybe it was luck, a sparse population or of course the often repeated ‘everyone always does what they’re told’ (hmmm). Also it started off well but things have become quite fragmented recently (different agencies issuing rules about different things at different times, in different regions, much to the dismay of anyone trying to plan anything). In short, whilst interesting, there’s not really any useful comparison that you can make between the US and Finland in my opinion.
Subjectively after living in both Helsinki and London it feels like Helsinki is even less crowded. I would say that there are fewer people who commute in to commercial areas from outside of the city than in London, and the commercial areas such as offices are generally a lot less dense, newer, and more spread out.
[1] https://www.hel.fi/hel2/tietokeskus/julkaisut/pdf/19_06_14_H... [2] https://www.ons.gov.uk/peoplepopulationandcommunity/populati...