For those who don't know, the object in the image is a tram. Trams are great because they run on electricity and not gasoline so they produce much less pollution than for example cars.
And this is an image of a commuter train. Those trains are also great because they don't pollute.
What is not so great is that not enough people use these services. The highways are crammed with cars (often with only a single person in them) trying to get in our out of the city centers. Trams and trains are great, but cars are bad because they pollute a lot.
What is not so great is that it costs you about 120 SEK to make a round trip from Södertälje to Stockholm. It's 160 SEK if you are travelling from Gnesta. That is to expensive. It takes longer and is not much cheaper to travel to Stockholm by mass transit than by driving a car. So if you have a car then you will use that to commute if you aren't particularly concerned about the enviroment.
Previously, it costed 40 SEK for a round trip to and from Stockholm. That price was much more palatable and quite a few people decided to use the mass transit instead of driving. It was changed because the current politicians thought it was to expensive for the state, but it was not. SL could have easily affored it, but the politicans prioritised tax cuts instead of social service.
Mass transit should be free, and it should be funded by taxes. Everyone should have equal and cheap access to travel for commuting and so on. Making the mass transit free is the simplest and cheapest way to drastically reduce carbon dioxide emissions and improving quality of life.