Both my bikes are aluminum.
Cannondale Quick CX (Alivio level) as my commuter / goofing-around-with-the-kids / grocery-getter / errand bike.
I put about 1000 miles a year on it. My longest ride on it has been 30 miles. More typical is 3 to 20. And it's fantastic for the use to which I put it. The frame is quite stiff, but I want it to be stiff since I've got a Tubus Cargo Evo (strong) rack mounted in back with a couple of Ortlieb panniers.
Cannondale Synapse Sport AL (105 level) as my road bike, for fun rides, hard rides, and distance rides. It's my default ride.
I put about 1500-2000 miles a year on the Synapse (it was more before I got the Quick). Its frame is really nice to ride on; the seat stays are bowed inward to absorb road vibration, the chainstays are contoured as well, for the same reason. The front forks are CF. I ride this bike anywhere from 5 to 100 miles, and it's comfortable the vast majority of those miles. Any discomfort is entirely due to me, not the bike. Sometimes I look at newer CF Synapses but I really like the utility of my aluminum Synapse. Sometimes for longer rides where I don't expect to be able to find water along the way, I mount a Tubus Fly Evo (minimalist) rack and a small trunk to hold additional water and snacks. The Tubus Fly Evo is so minimalist I scarcely know it's back there, and often don't bother taking it off when not needed. You wouldn't mount a rack like that on a CF bike, and if you did, you would always cringe over bumps wondering what your P-clips are doing to your chainstays. Meanwhile my aluminum synapse has mount points that work well with the Tubus Fly Evo, and the rack is not so rigid as to change the ride characteristics.
So I'm good with aluminum. I'll keep riding it as long as there are decent bikes made with it.