A look at the statistics are fascinating (not only PHP versions). PHP 7.3 is almost a blip (it does not show in the chart), but will likely pick up speed. 40% are already on 7.0 or greater. A full 24.6% currently are running PHP versions lower than 5.6, something that will take a LONG time to change.

About 20% are running very old WordPress versions.

Looking at RTL locales, it is interesting to me that 0.8% are Farsi, while Arabic is only 0.3% (surprisingly matching Hebrew that I expected to be much lower than Arabic based on population).