This work earned the 2020 Nobel Prize in Physics: https://www.nobelprize.org/prizes/physics/2020/summary/
As more telescopes come online, there'll be more data available for this type of stuff. You gotta realize that when a telescope only looks at something once per year, it takes a long time to gather enough data for these types of images to be created. My go to example is the motion of stars around SagA*.