Some people work hard but aren't as lucky with the "being rewarded for their hard work" part. A grain of salt required for lucky people's advice. Especially the one with short memory and rose tinted glasses (as other commenter noted, this guy seemed to have burned out[1]). It's Probably more a rationalization to himself and people around him (his kids and wife I guess) sugarcoated as an advice.
Second is people saying "I can retire early if I work hard now" I mean sure. Toil away the best years of your life when you have the most youth, beauty, energy and freedom so you can enjoy leisure when your body is aching and getting a good sleep is hard. I'm not that old but did my stint of "16 hour days 7 days a week" at startup and my reward was useless options and chronic illness flaring up (requiring two minor surgeries down the line). Glad I tried it out tho (minus the physical and mental health toil)
Work life balance slows career. Prioritizing work might speed it up. But I'm not sure the point of a career is the goal, but the journey itself.
I'll do some overtime and all nighters when it's required, rewarded, and I feel like the work matter to me.