You're really missing the whole point that these kinds of delays propagate through the whole network. All trams after this point have to stop or they start congesting the roads. So all lines that share the same track and switchovers might have to be stopped too if there aren't enough alternatives (which tram tracks usually don't have a lot). This can easily halt a huge part of the tram network depending where in the network this congestion is.

And when the congestion is finally resolved it might still take a long time for everything to finally run smoothly again. You're also looking at worker overtime, depending on how long it took the car to get removed. They might not be allowed to drive further anymore because they are over their time limits, so now you have to shuffle around tram drivers too adding to more delays.