Many people struggle to motivate themselves to do their part on huge collective action problems like climate change. That's why national and international political action is needed, and in turn needs smaller groups of individuals to put in effort supporting campaigns for such action. That said lots of people do care in their daily lives and also put that care into practical individual action - and have a fun and meaningful time doing so. In my experience not owning a SUV or any car at all doesn't feel like "not having fun". It feels sensible and what I have good reason to do and it feels purposeful, a part of doing what I can to cause less harm in this world, from the lucky situation life has dealt me. I understand that some people really need a car for work, especially in car centric regions. But almost everyone has a range of other things where they can do their part and act to improve things.