It has been over thirty years since PMU was invented. The deployment of PMUs for grid monitoring has been limited, with a few thousand units in use by the U.S. utilities in 2022. This statistic would be considered a "non-starter" by the standard of high-tech breakthrough technologies. While there could be a tipping point in the future by which the PMU technology finally takes off, it is also arguable that PMU may not be the right technology for the future grid. We consider some alternative technologies that go beyond PMU-based monitoring for a grid with deep penetrations of inverter-based resources on both generation and demand sides with fast dynamics and rich stochasticity.