If you live outside of the subway system and need to get places (particularly in/out of the city) within a reasonable time-frame you're likely going to need a commuter rail pass. That jacks up the price substantially.
I did the whole "live in Boston and just use public transit thing" for awhile. Then I moved to one of those cities that MA likes to pretend doesn't exist and my transportation costs stayed about flat. If I had made heavy use of Uber/Lyft they probably would have decreased. My friend commutes in from Worcester and rides the train because of the tolls and the fact that his work subsidizes the rail pass. In a sprawling city with free/cheap parking there would be no economic reason to do anything but drive.
Yes, that is somewhat the point of this discussion. The money one saves on housing by living further from a dense urban core is often offset to a significant degree by transportation costs, whether those additional costs come from regional rail or driving.
When people say "public transit", they don't mean the periphery of a commuter rail system. They mean the core bus network and usually the subway. You're comparing the worst case of meaningful public transit to a city only built for cars. My hypothesis, if you lived in Somerville, Dorchester, or at most, Quincy, the numbers would look different.
Sure, if you specifically craft your living situation to not involve commuter rail (and don't replace it with Uber/Lyft) you can save money. But you'll spend the money on rent.
Bingo! That's exactly what the linked article is about. How much extra are you paying in rent? How much are you saving on transportation? What are total costs of [rent + transportation] in both cases? How much time is wasted on transportation when you're paying lower rent? These are questions that need to be asked.
Why would you not want to "craft" your living situation to give you the optimal setup? No, you can't have everything, but a "crafted" lifestyle that avoids need for transportation may be preferred by many, and may in addition in some cases be cheaper _and_ provide higher quality of life. Maybe not, maybe not for everyone; but those are questions that need to be asked, not simply have, "What are housing rental/purchase costs?" be taken as deciding question of what places have higher cost of "housing".
I did the whole "live in Boston and just use public transit thing" for awhile. Then I moved to one of those cities that MA likes to pretend doesn't exist and my transportation costs stayed about flat. If I had made heavy use of Uber/Lyft they probably would have decreased. My friend commutes in from Worcester and rides the train because of the tolls and the fact that his work subsidizes the rail pass. In a sprawling city with free/cheap parking there would be no economic reason to do anything but drive.