The teensy is so weird though. At least back when I played with them. They put a secondary chip which let's you flash over USB but they cover the debug pins and the only way to get serial over the USB port is to have a whole USB stack as part of your application. As a development board I would rather go with one of those STM32 backed boards and a knock off STLink, you need the STLink to flash, if you want DFU you can add that yourself, and you get a debug adapter.

Yes, the Teensy is pretty impressive too. I've used one in a project and came away impressed.

For everything Arduino offers that I've ever used I know of a cheaper board with better specs.

This has 100% been my experience, even with in-person shopping.

You ask for an Arduino, and the follow up question is: 'genuine or generic?'.

I don't think the Arduino trademark is that valuable, it's already well underway genericization.

> A competent engineer designing a devkit as simple as an arduino needs about 1 day of work.

Hah! I like to underestimate scope as well, but this is really something else. Definitely a competent engineer could make something like this. But a couple of months maybe. You won't even read the documentation for the chip in a day.

It’s not quite that easy, and besides the hard part is the SW. arduino spent years writing SW code and still does to make it easy to run, debug issues and provide support.

Also a million dev kits is unrealistic for vast majority of companies 5-20k is more the number I hard.

I have been modifying Arduino libraries for weeks, there is much more work in them than just a single day. Granted replacing the Arduino IDE with Autoconf took 3 days. (2 and a half of which were spend on analyzing what the IDE does.)