It is not an either or. Best thing average jo can do is auto set up to overpay their tax efficient retirement vehicle, make sure said vehicle is an index of US share or perhaps an international mix with a decent US weight, and buy a residence somewhere there is and probably will be high demand. So NYC, London etc. (due diligence assumed)
With that you can spend all you earn, you will be forced to save a bit naturally due to mortgage repayments and the retirement setup and you have
diverse investments.
Once you gave equity you can borrow to
invest more.
If you get any bonusy kind of money like RSU then invest that as you go along unless you need it to create more cushion for your mortgage.
They don’t want a quarter inch hole, they want a lazy sunday afternoon bbqing with their family and showing off their beautiful new outdoor decking to their friends.