You're a nihilist whether you realize it or not. I find nihilism the most irrational life philosophy compared to existentialism or absurdism (which is the most reasonable). I believe there is no way to verify someone's life worth on a universal scale, because there is no way to verify inherent meaning to life in the universe, but in terms of yielding results that leave a lasting effect, you can measure how much someone has contributed to the human race.The notion that one person's life were more meaningful than another is an illusion.
Your legacy is as fleeting as your life, when you're dead the only thing you are is a memory, depending on what you did, a few people may remember you but once they die no one will remember you. Once humanity comes to an end, all human achievement will be equally useless so wake up.
The value of life is in the moment, enjoy your life to the fullest so you can die with a smile on your face, knowing you had a blast.
Of course, none of this is to say progress isn't good, go for it but don't lose sight of what truly matters in the end.
I agree that you cannot say one person's life was more meaningful than another, but that doesn't mean you can't say one person had a larger lasting effect during their life time than another.