My rPi pihole hasn't had a single hiccup for years. Multi power outages and everything. I actually thought it was going to be a way bigger hassle over time but its been smooth sailing.
I've had about half a dozen Raspberry Pi in total (only 1 through 3), and many dozens of SBCs, and I found Raspis generally unreliable except for the Raspberry Pi 1 (model B), which is extremely slow for anything nowadays.
The longest I've had running was a The Things Network gateway on a Raspberry Pi 3: OK for 2 years, then it killed the sd card (not corruption, it just wouldn't work anywhere anymore). I set it up again and it killed the new card within a week. Again, and within a month. I gave up and it sucks because the LoRa shield is Raspberry-specific.
A Raspberry Pi 2 died just because while decoding ADS-B. SD was fine.
For the rest of the experiences, I always found some data corruption at some point. Often hanging and needing monthly reboots.
The only worse SBC (and it wasn't really an SBC) I've experienced was the Cubox i4-Pro. I eventually lost it, and I'm almost glad, weekly data corruptions and crashes, underwhelming performance and very fickle behavior overall.
Other <randomfruit> Pis have turd-tier hardware support but whatever you manage to get running tends to be reliable. Pine64 (the oldest model) is so far the only SBC I haven't seen crash, trash an SD card yet, or have FS corruptions yet.
