I wouldn't hesitate to buy carbon over aluminum. A well made carbon bike frame should last you many years. To that point, I have a 20 year old Parlee (I bought the frame in 2020 as a covid project) which is always a joy to ride.

That being said, the carbon Topstone isn't quite one to one with it's aluminum sibling. There's the integrated suspension and lighting system, and the geometry is a little different. The carbon frame on paper looks like it would be a bit more responsive (shorter chainstays, slightly steeper head angle, shallower bottom bracket drop).