Every time I stumble upon an interesting board in the official product lineup I find that it's marked as 'retired'.
There seems to be a constant churn of new products that don't stick around for more than a couple of years. There's a good chance that a board you buy today will be obsolete and permanently "out of stock" before you have even completed a project using it.
The only stable products are the ancient low end models that continue to be priced at a level that makes no sense given the plethora of clones and alternatives that have more capabilities, such as the ESP range, the Teensy or the Arduino compatible abstraction layers offered by TI or ST.
Looking at the Arduino store today there are 20+ boards. I have no idea what niches in the market half of them are supposed to fill. How many of those will still exist a year from now?