It's so easy to get tempted into feature bloat these days. You need a microcontroller for some simple set of features, like doing PWM control on a fan and handling a rotary switch, so you get something like a Seeed Studio XIAO ESP32S3 that's the size of a thumbnail and costs like $10, but then all of the sudden you have way more processing, memory capacity, pins, etc than you need, and oh hey, you now have USB, Bluetooth, and WiFi, and surely you should at least do SOMETHING with them, right? But the hey, for just a little bit of extra cost you could upgrade to a XIAO ESP32S3 Sense, and now you have a camera, microphone, and SD card, so you can do live video streaming, voice activation, gesture recognition... .... it really creeps up on you, because there's so much functionality in cheap, small packages today.
The irony though is that nobody really seems to bundle together everything one needs. Like, could we maybe have such a controller that also has builtin MOSFETs, USB + USB PD charging, BMS (1S-6S) functionality, and maybe a couple thermocouple sensors? Because most small devices need all these basic features, and it's way more cost, space, weight and effort to integrate separate components for all of them. The best I've found is a (bit overbuilt) card that has USB + USB PD (actually 2 of each, and reverse charging support), BMS support (1-5S), one thermocouple sensor, and a small charging display - but no processor or MOSFETs.