I'm pretty happy with my Mazda 6 but I don't exactly have a great frame of reference since I buy cars for a generational duration
Have had some minor mechanical issues over the years. Water pump developed a crack somewhat recently and had that replaced $600 w/ labor IIRC. I have a broken wheel bearing right now that needs replaced. Ignition coil replacement (thankfully on the front cylinder set, $25 by me instead of paying someone to dig to the back)
Replaced a few rotors. Wear and tear stuff not too big a deal. Brake pads need changed too (The factory brake pads are AMAZING, last forever)
Also the seats were garbage in terms of durability, I had them re-covered.
The only big complaint I have is the particular model I have can't turn for shit. But it's not often I'm pulling U turns.
Currently @ 176k and will probably last another 40 before something serious breaks down that isn't worth fixing.