Turnkey microcontroller projects can be really quick. Adafruit and Sparkfun sell many of their breakout boards with special cables for I2C now, so you might not even have to solder anything. From there, you can drag a Python script to the microcontroller (which appears on your PC as a flash drive).

Building enclosures for these projects used to be an annoyance, but everyone provides CAD models of their stuff now, so you just kind of lay it out in your CAD program, extrude a box around it, and print it out.

Never been a better time than now to be building sensors and that sort of thing. (Even with the STM32 shortage!)

As for the Raspberry Pi -- my rule is to treat embedded systems like hardware. Download a Linux image with the software you want on it, copy it to an SD card, plug that in, and go. I use this model for Octopi and while I might have changed the password and uploaded a profile for my printer file, that's it. If the RPI blows itself up, $35 and 5 minute fix. What version of systemd is running? Don't care. How close is the clock to Coordinated Universal Time? Don't care. It's an appliance and the time on the front is blinking :P

(I spent most of my free time this week unbreaking my Beaglebone that I ostensibly don't treat that way -- I log in and fuck with shit. Though when debugging failed I just blew everything away and copied over what I saved in the project's Git repo. It was enough to be back up and running with no loss of functionality. I guess the key is: don't let it run away from you -- it can be an endless time and energy sink.)