Call or visit the Swedish Tax Agency if you want further info, such as personal identity number ("personnummer" - think Social Security Number but used for absolutely everything), taxed income, identity and full info of parents (including mother's maiden name - so much for that), etc. You don't have to tell them who you are or why you want this information.
Enter a street address on a site like ratsit.se and you'll find all the people registered on that particular address. I could go on. When I talk about this with friends in countries like Germany and France they're often flabbergasted; in Sweden we're so used to it that we think it's natural. We're basically doxxed by our own government by default. A stalker or identity thief's paradise. It's messed up.
Many Swedish online shops will happily send you goods along with an invoice that you pay later. The invoice option is often only available if you provide your personnummer - which as I mentioned is public information, a phone call away - and have the goods sent to the address tied to that number. If you live in a house with a mailbox outdoors, a thief could order stuff to your address and empty the mailbox before you. "Stuff" could also be things like mobile phone subscriptions and whatnot.
Or, having your personnummer, someone could send a form to the tax agency to have your official address changed! I believe they do send a letter to the old address saying the address has been changed to <new address>. But there's time to do bad stuff in between the time of the change and your discovery of it. (If, indeed, you do discover it. You might be traveling somewhere, a fact that might've been gleaned from your social media activity.)
And, as breakingcups points out above, even if it were the case that sound security procedures were implemented in Sweden, that wouldn't matter much for the numerous non-Swedish services most Swedes use every day.
Anyway -- people being able to do stuff in your name is just one thing. I don't want the whole world to know my address, or marital status, or date of birth, etc - period. It's about privacy.
Like domain names, privacy when you have a company is hard.
You MIGHT still be able to search by name in the old fashioned way, by going into the office, but I am uncertain about that.
No, not all of the time, but very often enough to make it useful for social engineering.