All about Philosophy.
Many of us spend our lives thinking of science and philosophy. Looking for answers to the meaning of life the universe and our place in it. And then eventually we die. Have we not accomplished anything? Does our knowledge somehow live on beyond death? What is the point of seeking knowledge?
I'm not sure why you think that we're all gonna die - our heritage will live on, probably forever.
I believe that the universe is infinite, both in space and in time. As such, there is a probability that humanity will continue to exist forever - and so will the consequences of our actions. Therefore, life is not meaningless.
You would have died in early childhood had you not sought knowledge, but fortunately knowledge-seeking in inbuilt and needs no justification.
Edit to add: This reminds me of a poem from Cat’s Cradle:
Tiger got to hunt,
Bird got to fly,
Man got to sit and wonder “why, why, why?”Tiger got to sleep,
Bird got to land,
Man got to tell himself he understand.
It's nice to have something to pass the time until we eventually die.
Knowledge-seeking is not necessarily a selfish act. Ideally, knowledge is something to be shared, to propagate, to enhance our species in the long term.
Most of our advancements in science, medicine, philosophy, etc. weren't discovered in a single lifetime. It's the culmination of hundreds of thousands of researchers, scientists, and even some laymen who got lucky and stumbled upon a discovery. And over time and many generations, we build upon the knowledge that's already been discovered and find new and more complete knowledge that benefits our world.
There are some who are fascinated with a single topic and dedicated their lives to researching it. Then there are autodidacts (self-taught learners), like my late father, who spend their entire lives studying everything they can get their hands on. And of course, there are those who don't care to learn and just try to exist and get by until the day they die. Plus many other flavors of knowledge-gatherers in the world.
Is any of this wrong? No; everyone is free to pursue whatever knowledge they can or want, or even a lack of it if they desire.
Is it pointless? Not really. As stated before, your knowledge can be passed on to benefit future generations. Or if you keep to yourself, then perhaps you're learning for your own self benefit. Being better educated about your world and yourself can only serve to help you make more informed decisions in your life.
What's the meaning of life? There's isn't one specific meaning. We happen to exist, and whatever you decide to dedicate your life toward is what gives you meaning. So no pressure about meeting some imaginary goal or standard of accomplishment. Do what makes you happy and what benefits those you love and care for, and you'll carve out your own meaning in life.