Aldi is all over the world. Ran into them everywhere from Australia to the US. Ironically, Lidl is just a copy of Aldi - and by copy, I mean that it is HARD to tell the difference between the two. I'm sure Aldi loooves Lidl.
As I business owner myself, I can tell you that markups are not random - I shop at (and pay for the privilege of) a clean, large, well presented selection of food when I go to a Prisma or Citymarket. I am quite sure Lidl executives are just as well paid as the Kesko people. If the big stores with the bigger markups went away, would you really be happy that all supermarkets in Finland were tiny and ill stocked, dirty and kind of hole in the walls like Lidl?
Also remember that markets like Hakaniemi sell Finnish grown foodstuffs from small farmers. Without economies of scale, they ARE more expensive to produce and get to you. Hence, the mark up. People buy those because a) they trust Finnish grown products and b) they want to support Finns. I think there is an assumption that those markets are to bring food stuff cheaper - when really, they are just as often about getting homegrown, organic, locally produced product - by Finns for Finns. Young people in technical fields in Finland never appreciate the distinction of Finnish farmers and foreign produce until they get laid off when their divisions are outsourced to India or Hong Kong.
Honestly, I HATE paying VAT for my business. But then I get sick or my sister tells me how much her day care bill is in America, and suddenly I remember WHY I pay so much.
Finally, seriously, do you really think Kesko or S-group are the only large corporations with execs who get paid billions while their workers work min wage? Nearly anything you buy that comes from a large corporation has serious human resources issues. You going to boycott the world?