Recently was on a trip where we went to Oslo for a couple days. Even when we were digging on things to do many sources we came across mentioned to just skip it.
While there are much more adventurous places to see in Norway, in our case we were tagging a few days on to an existing trip.
We loved Oslo, and as I was staying for an extended amount of time in Copenhagen I think it was well worth the short cheap flight.
We ended up with 2 days in Oslo and 3 in Bergen, which I think was a decent balance.
There's nothing extrodinary about Oslo, and I think 2 days is plenty, but here's my case:
Museums are decent, and some buildings in the town are their own mesum being a bit older (not super old Europe-wise)
Just a pretty setting by the water, great public transit infrastructure, for North Americans English is widely spoken. Dining options are fantastic (although not cheap, like anything in Norway), hotel rooms were cheap compared to a lot of other destinations. Throw out your water bottle, their tapwater is better than most bottled water. Also the people are fantastic (in Norway in general) and most will talk to you at lenght if they can.
What did we do in a couple days?
Couple great meals including one in Oslo's oldest restaraunt (built 1750 or so, restaruant opened 1850 or so), some cheaper street eats, didn't do the floating sauna because we did it in Bergen, but you can here too, checked out a couple museums one being a fun "Flop
museum, visited 2 of the top 50 bars in the world for 2025 (one of which is in a historical pharmacy from around 1850 I believe), window shopping (too expensive to buy!), had a stroll through a park with a stream right by a fantastic food market, had a $9 coffee, saw a couple churche.
Other than hotels it's not cheap, but if you're in a scenario with 1 - 2 days to kill and you're looking for something calm and not running around all day fighting tourists to take pictures of old things, may be worth looking into.