SpaceX can also be highly profitable which generates tons of tax revenue and jobs (which were otherwise going to Russia or simply not launching into space at all due to cost). It also offers cheaper ways for all governments to launch satellites and other research/national defense, freeing up capital for other social things.

And as you've mentioned it helps create new technology opportunities which also generate efficiency/value/taxes like space internet and in the longer term mining without destroying our planet.

There are plenty of benefits to society. Although there will always be a contingent who thinks everything not an altruistic social giveout = bad use of excess capital.