Buying an apartment is expensive, and problematic even for well payed young people. In central Stockholm prices are around 1000 USD / sq feet (≈10000 EUR / sq meter), and you need a 15% down payment. For a 400 square feet single room apartment that's a down payment of a full years post-tax salary. If you manage to save 20% of it, then it'll take you five years.
Until you can afford it, the best option is market-priced second hand contracts. Which work well enough, but are quite expensive and very insecure. The landlords often bought the apartments with the intention to live in them, so most contracts are semi-temporary.
First hand rent-controlled contracts are extremely hard to get and basically not an option. The queues are decades long. There's often a 2-300% difference between second-hand (market) rates and first hand contracts, so once someone gets such a contract, they'll never move out.
Of course the lower cost of rent-controlled apartments helps the inner-city be more diverse, allowing people with lower income living there. But there's also a large share of well-of people that have gotten their contracts via connections, or who have just been in the queue for a really long time.
I really hope that the rent-controls are abolished in my lifetime, but there's a vocal large public option for them, so I'm not too sure...