I'm interested in science so am only interested in robots which are demonstrably far more appropriate for the work: the evidence is pretty clear from Voyager to Webb to Ingenuity and so on.
If we want to colonize far away planets, much less other solar systems and ultimately galaxies, why send a human when a robot is far more appropriate to the problem?
Most of the science humans do in orbit is about keeping humans alive in orbit. Important, if you think putting humans in space is important. I don't, apart from tourism and other recreation. Let the private sector pay for that while government research can do the important stuff of value to all humanity.
Because Earth is currently a single point of failure. If we want humanity to survive planet-wide catastrophe, we need to send human civilization to other planets.
That is a justification, but surely not the only one. For example, humans will eventually want to colonize the moon and other planets.