When you’re lonely, you don’t become cripplingly hopeless and withdraw from life? You just contact some friends or easily make new friends and have a good time and carry on with life?
When you’re driving your car and everything is fine until you come to a stoplight, you don’t suddenly become depressed at the stoplight like I do?
When you wake up every morning, you don’t have crippling existential dread? You just get up and go about your day cheerfully, without analyzing the futile meaninglessness of the big picture?
The meaninglessness is still there. What I suspect is the biggest difference is the headspace surrounding it. If there’s not inherent meaning to life, then that frees you to create your own with your own goals and desires and whatnot. If there’s no inherent meaning, then any meaning we as humans come up with for ourselves is the meaning. For some people, that’s religion. For some, it’s taking care of their loved ones. For a few of my friends, it’s to play as many video games as possible. For others, it’s to work as much as possible. The beauty of it is that they’re all right, the meaning of their life is what they make of it. You are what you repeatedly do.