I have a love/hate relationship with roundup posts. I love reading them. I hate writing them. That's why I haven't really summed up my 2019.
The best summary of 2019 in dataviz that I've read comes from Data Visualization Society founder Elijah Meeks. It covers the key people and projects of the year, as well as a little of what to expect in 2020.
You should read it: