All hobbies are expensive. At least with flying, I can make it a family activity since my wife prefers flying over driving to places anyways.
Example, before we had the plane, we would do a weekend trip per month by car. Going for a weekend trip by car also costs money. Usually a 3 hour drive can be a 1 hour flight. So, gas wise (our car uses lots of gas) it's almost a wash. Depending on the destination, the only added expense is airport parking.
Before we had a plane, we would go to Florida for part of the winter. Never by commercial airline because we have pets who I will not put into cargo. So, we drove. 20+ hours one way. Now with the plane, we fly. 7 hours one way. Again, gas is about a wash.
Once every quarter, I have to go see my employer. He reimburses me travel cost as if I was driving, a flat rate per mile. He doesn't care how I get there, he'll just give me miles x $$$. Driving is about 7 hours. Flying is just over 2 hours.
So, the only actual added cost is hangar, insurance, maintenance, upgrades. The last one is on me. I can spend on it or not. If I have the money, I do. If I don't, I don't. Hangar and insurance isn't all that much in my opinion compared to other hobbies.
Maintenance is the big wildcard. If all that's needed are oil changes and standard annuals and standard ADs I knew about prior to having bought the plane, I still think flying is a cheap hobby compared to some other hobbies. If something breaks, it can be expensive obviously and I guess one will have to know for him/herself what that threshold is.
Lastly, CapEx is obviously on the higher side for planes. I own the plane, no loan or anything on it and I would argue it's holding its value so I'm not too worried about the CapEx.