But if their economy did worse than their neighbour, what was the point of avoiding invasive measures? They have more deaths, more cases, and worse economic output, what exactly is successful here?
Quality of life. Additionally "our neighbours are doing something wrong and bad so we should too" is not a justification.
Lockdowns cannot stop COVID deaths and in the beginning nobody claimed they could. The idea that Sweden has performed worse than Norway is a massive goalpost shift that is rightly being called out as nonsense. Especially because it's clear how much corruption there is in these figures. Did the UK really do so badly compared to its neighbours, or is that a result of the health body defining a COVID death as anyone who ever tested positive and then died at any later point, of anything at all (i.e. all COVID infections are fatal according to UK stats).
Sweden has a population of ten million people and an economy very tightly tied to the rest of the EU, so exactly what measures we did I don’t think made a huge difference for the economy.