Adafruit is pretty clearly the front-runner these days in the educational/hobbyist market, Arduino (and even SparkFun) have fallen by the wayside. My only gripe is the focus on micropython these days, it can introduce a barrier later in the learning process when you eventually need to leave the nicely organized sandbox. They still support the “Arduino” C++ libraries, but uPy is the default.
Adafruit actually focus on CircuitPython which is a fork of Micro Python but takes some of the complexity of Micro Python away. I don't personally like coding in C++ as I started my career with Perl then PHP and Javascript. Writing Python in my own choice of text editor instead of the Arduino IDE is much more my style.
A couple of weeks ago, I bought a 'sensor kit' from Amazon for my son to use with his Raspberry Pi. It includes some input devices (e.g. button, moisture sensor) and output devices (e.g. LED) that can be plugged onto breadboard.
In my experience LLMs can code C++ for the Arduino framework pretty well these days. The mistakes they make, like wrong pin numbers, are pretty language agnostic.
