Living on Mars and space exploration
I was listening to the Mostly Technical podcast #54 hosted by Aaron Francis and Ian Landsman and they were discussing a topic wether a SpaceX marketing about going to Mars makes sense or no. Right out of the gate I agree with Aaron in that discussion. I do agree with Ian that the "dream" about having colonies on Mars and having it as a "Plan B" in case Earth goes to shit is totally ridiculous.
Lowering cost of sending stuff into space
I see the successful launch and landing of the Starship as huge opportunity in unlocking great potential for space exploration and the whole space industry. With lowering cost of getting stuff to the space will enable us as humans build larger space stations, and maybe some space stations (launching pads) on the moon and elsewhere in the solar system and that is extremely important if we want to properly explore and maybe even mine resources from the space. Why is the moon base so important? It's much cheaper to launch from there or maybe just having a refill station there would be great time/cost saving achievement for space exploration, due to its lower gravity thus lesser fuel need to launch something from there.
Unimaginable inventions
From the history we know that a great effort in space exploration has led to previously unimaginable inventions stepping from that. I think it's not exaggeration when 1/4 of our economy today is directly tied to the innovations that were made in order to get a human to the moon. What innovations I am talking about? Personal computer, smartphone, GPS, the Internet. We simply cannot imagine what will come out of our current efforts in space exploration.
Political incentives for space exploration
As far as I understand how the budget for NASA and other similar agencies are distributed is not specifically tied to a "vision" or a goal. It is true that during the Moon Landing phase of space exploration the budget for NASA was much higher than it is today. However NASA and other agencies don't have to have an green light from the government on how to spend that budget witch gives them more opportunities to launch more missions on the same budget, thanks to that saving that SpaceX potential provides.