Like most people, I entered COVID as a normal hobby geek with a Linux server I played around with and a healthy hardware habit with a side of home automation and DD-WRT. I emerged from COVID enrolled in college, now with two servers (one new build, one rebuilt from my first one), two Pi, multiple instances of Home Assistant (one dedicated) and putting sensors on everything a sensor could go on and rewiring switches for wifi control of overhead fans, flashing every compatible router I could find on Amazon Warehouse with DDWRT in my home for an ad hoc mesh network (no, it didn't work, but I didn't care) while cabling everything to switches and creating a really hilarious network deathtrap tripping hazard, a massive media library (discovered Handbrake and making multiple resolutions) and a Sonos home theatre system. And yes, played an unhealthy amount of Animal Crossing and got an NVIDIA Shield Pro for streaming and Plex, as you do. I'm sure everyone can relate.
SBC's were the natural escalation; I had credit card bills to pay off and that's going to take a while.
I gatewayed with Pi like ten years ago but it took off during Later COVID when I noticed my credit score and started testing it as a NAS, Media Server (later: Cassiope Media Server, my second end to end Linux build), then got into learning about the kernel itself. I already had an Odroid (Home Assistant Blue) so why not go on, so project-based SBCs seemed healthy; I had a reason for buying one. This led to more Pi's--as I couldn't use Kernel Pi (Eurydice) for it and Andromeda Pi was masking my personal network, then I needed one for a Pihole (Iphigenia, Hecuba), which is how I ended up with a BeagleBone Black (Medusa) for an Open Thread Border Router. Still pretending I wasn't just collecting them like cats, I networked them together and just enjoyed looking at them and making them matching banners with figlet with the excuse I was learning how to do network-wide deployments over SSH (true) and learn Debian OS (technically, I am doing that) and started PoEing things (my credit card bills may not be getting lower, no).
The count stands at a total of 9: one (1) Pi Zero W, one (1) Pi Zero 2 W, one (1) Raspberry Pi 4B 4G, two (2) Raspberry PI 4B 8G, one (1) Odroid N2+, one (1) Beaglebone Black, one (1) PocketBeagle, and one (1) BeaglePlay. (Other: two Linux machines, Watson and Cassiope). Yes, they all have names and technically, each is associated with a project. The BeaglePlay's (Circe) associated project is 'create my own documentation on what it does because Beagles don't document'.
So which ones do you use, why, origin story, feelings: go.
(I'm moving in a week and half my hardware is being packed. I'm about to have to take down my network and Home Assistant and may be freaking out. I'm not sure I know where any light switches are here, either.)
Oh... that's a huge question. It's been a long time now. I have used these in various projects for a lot of engineering, research, home networks, and embedded projects. I almost always run them headless over a serial console then SSH in for management.
I do a ton of other work with embedded microcontrollers too. Lots of ATMega and SAMD boards, plus a bunch of ESP 8266/32 variants.
I think, you have a problem.
But a good one if you can afford it
There are way less productive and interesting hobbies and interests.
My honest opinion: literally any hobby or interest that makes you happy and makes your life better is productive and valid and should be encouraged, but i do have an acquaintance who once in a while forgets I am a nerd with a nerd son and a nerd's ability to google productively and extensively. I do not need to play to know how much it costs for serious gameplay when you're into Magic the Gathering so you really want to talk about my forays onto Newark, Mouser, and Adafruit? He does not.
(Honestly, I'd bankrupt myself if i was into Magic the Gathering; I am not a gamer and stick with stuff like Animal Crossing and Stardew Valley and Final Fantasy because I only have two modes; casual and competitive murder if it hits me right. Even thinking about getting into DnD makes me a little nervous; in theory it seems like I'd be okay but that transformation into Seperis-Hyde is really distressing.)
Fun note: I was in Magic: The Gathering from about 1994-1995 or so. Just after the second generation of cards was coming out. I had some seriously rare cards, including a few first gen ones that I picked up like Lord of the Hunt. I had a Lord of the Pit, multiple angels, and a Shiva Dragon. It was good times, but it was getting expensive....
To save myself I sold them all and bought a Warhammer 40K Epic Tyranid army.... Out of the frying pan, in to the fire.
At least the Tyranid Epic army was so OP that I never bothered to work very hard in battles and won anyway. That needed some serious nerfing.