Wait for the 2020 iPad
One reason not to buy is that you are looking for the newest model. There is a good chance that Apple offers up a new 2020 iPad with a 10.2-inch display later this year.
We typically see refreshes to this lineup once a year, so you can count on something. At this stage, it is looking like the announcement won't be until the Fall. The current model went on sale in September 2019, so Apple is unlikely to refresh this at a Spring or summer event.
We don't have major rumors about a new 2020 iPad with a 10.2-inch display, but there are some reports of the 2020 iPad Pro models, so if you are on the fence between this iPad and the more powerful iPad Pro you may want to wait until the end of March.