Abstract: Observations of the cosmic microwave background (CMB) probe a diverse set of fundamental physics in both the early and late universe. CMB measurements are a cornerstone of our now exceptionally precise Lambda-CDM model of cosmology, however, many questions remain. Did an inflationary epoch occur a fraction of a second after the Big Bang? What is the nature of dark energy? Is the Hubble constant controversy new physics or simply measurement systematics? I will describe the SPT-3G receiver that is currently installed on the South Pole Telescope and how it is measuring the CMB to answer these questions. Now starting the fourth year of survey observations, SPT-3G data is already providing tantalizing hints about what scientific goalposts will be possible in the very near future. I'll highlight a few of these results as well as providing perspectives on the upcoming CMB-S4 experiment.