I used to be a Ferrari fan when I was growing up because I enjoyed the history behind them but they done some questionable things at one point and I pretty much just started following drivers instead.
American sports I have drifted to different teams at various points in my life if the feel around them has changed ie: them not standing up for something important to me etc.
That is the major advantage to not being from a team's hometown - I don't feel obligated to support them if I feel they don't deserve it anymore - unlike my partner who is from a place where supporting a certain team is very much expected of you depending on where you live and even what religion you or your family members are.
That said, my heart usually does keep the flame alive - I will always be a Steelers fan for instance, even if I couldn't bring myself to "support" them for a while.
Tbh, the sports I still tend to follow are things like ice skating and gymnastics which are more about the individual for me. I still follow cycling, which is very much a team sport, but again I tend to be more interested in individual riders rather than their teams there as well.