The budget to project a brand new car with a total new chassis is high and it's cheaper taking a Jeep chassis.
There is though, that thing, called the Giorgio platform, and it just happens to be fully developed and praised for being the best chassis in the industry at the moment (exlcuding Porsche, Ferrari,...)
And on top of that it is modular, so it can be shortened or lengthened. It also costs billions to develop, so it would be anything but stupid not to use it on future Alfa Romeos. It would also allow for the new compact SUV and new Giulietta to (let me put is simply) destroy the competition in drivign dynamics in this class.
But no, they rather go down the old route - reworking flabby front wheel drive subpar fiat platforms. Not that every review out there praised Alfa for finally stop doing just that and developing a proper game-changing benchmark of a platform.
The Giulietta was big progress from a Bravo. Sometimes the differentiation is just as good as trying to make a whole new car. And that rarely happens. The 500L is a Renegade. An Alfa Jeep can be good especially if itís got aluminium etc like Giorgio has adopted.
Alfa Jeep can only be good, indeed. Just like Giulietta was good at best. But it will never be absolutely brilliant drive like Giulia and Stelvio are.
I would call this decision a huge relaps to old habits and wrong decisions. And just after 3 years after the introduction of the best decision FCA every made with Alfa.