The only correct item here is about Systembolaget -- the state-run liquor store. Everything else is outright wrong. Prices are more, but not 2x or 3x more. And on many mid-priced wines the prices are lower due to buying power.

The major chains are either private, partnerships, or Franchise models -- ICA, Lidl (German-owned), Hemkop (Owned by AxFoods), Willys, etc.

Also, though grocery stores are not 24/7, most are open 7 days a week up to 10 or 11pm.