What is the one thing all life has in common? Reproduction. Literally the only thing you need to do to pass on your legacy is have a baby. Nature isn't deep or anything. It's really pretty basic.
That’s not really ” meaning of life”. You’re making the circular argument ” the meaning of life is to create more life”. Yeah, and why are we supposed to create more life?
This is exactly right. As much as some people don't want to hear it, this is the one true answer. This is what all life has in common, this is what defines a successful "life" on a global biological scale.
If you're worried about legacy, reproduction isn't the only thing you can/need to do. Ensuring your legacy survives the following decades/centuries is more important than the actual act of reproduction, IMO. Otherwise, if your legacy can't survive and thrive, what is the point?
Basically, making sure your environment isn't a hellscape should be priority number one in ensuring your legacy.