Cambridge is small enough, and cycle-friendly enough that nothing is more than 15 minutes away. Bumper-to-bumper is a choice (assuming you live reasonably near the centre)
As for living in the city, you either have to share with someone or pay exorbitant amounts for something tiny. And what are you even getting for the money? In London you get to live in a world-class city with the best public transport in the country. What do you even get in Cambridge? It's only famous for its university, and that is off-limits for plebeians.
The problem is when you get a job at one of the surrounding companies as most of them are outside the city and once you start planning a family you tend to move out of the city as well.
Then your car is your only way to get to work basically as the city and surrounding region is not dense enough to warrant implementing good public transportation.