I don't understand this. Genuinely. Greater Reykjavik has about 300k people in it I think
That's closer to the population of the entire country. Granted over 50% of them do live in and around Reykjavik but that still makes it about the size of Southampton and any number of minor cities in Europe. The rest of the population is mostly spread across tiny villages.
Lombardy isn't London either but we still tried to learn something from their mistakes. They didn't escape the virus having an impact simply because their region isn't one of the biggest cities
Lombardy is very densely populated, highly polluted and home to one of Europe's major cities, Milan.
So I don't understand why these smaller success stories are dismissed
They're not dismissed at all. Good for Iceland. But it's like all those stories praising New Zealand for their approach - yes they did do very good work but it's doubtful how it can be applied to a major European country. Same with Iceland. Its demographics are totally different from Britain or most other European countries, so what works there really isn't a model for most other places.