Most educational
The Pi has many lessons to teach. The most important (and, apparently most ignored) is the importance of an active user community.
Since its inception the Pi has, more-or-less, held its price point. A feature almost unknown in the tech world. Yet, it is still the go-to product, with seemingly unfaltering popularity, for people wishing to explore the complexities of making an LED blink.
Why would this be, when there are many, many, alternatives. Some at a quarter of the price of the Pi? (the Nanopi Neo springs to mind - not least because I have a couple on the bench beside me). The secret of the Pi's success is that users do not feel the product has been "tossed over the wall" to them. There is a lot of support available - although most comes from the community, rather than the vendor. And that support is vital: both for newbies flashing their first LED, through to those trying to push the envelope without making smoke.
Although the Pi is a venerable institution, hardware-wise many suppliers have blown past it. However, those suppliers have failed to take the Pi-killing step of investing support in their products. Whether that is supplying anything more advanced than a buggy and limited Linux 3.4 kernel, documentation for how to map the IO, or libraries, utilities and advice to ease the learning curve.
For that reason, I feel the Pi is on rather thin ice. All it takes is for a single far-eastern supplier to fill those support voids with Pi-compatibility, documentation, code and a half-modern distro and the Pi could find itself in an existential crisis with smaller, faster, cheaper and smarter products leaving it standing.