Be careful with the gear you use on your Pis, just like any system. If you’re using a no-name USB-C power supply and dirt cheap generic SDHC cards, you will likely have problems. By default, the Pi4 doesn’t come with a power supply and while you might be tempted to power it from your PC, spend the money for the official power brick, or, even better, get the official Pi Power over Ethernet hats. For SD, buy from a reputable source and get a brand name (Samsung or Sandisk).
This is anecdata from my part, but I’ve got eight or 10 Pis running (Flightaware/ADSBexchange, PiHole/Influx/Grafana/Wireguard, a couple of Octoprint, Home Assistant - with a relay HAT for triggering dampers, Showmewebcam, and a handful of other things). Once I switched to good power supplies and good SDHC cards, my problems went away. My most heavily loaded machine is the PiHole machine which also has influx running and writing to the SDHC card - it’s probably a ticking time bomb, but it’ll celebrate it’s fourth birthday on the same card in two months.
I walked into the Cambridge Raspberry Pi shop on launch day and bought a Pi 4, a power supply, and an SD card with NOOBS. It isn't my hardware that's at fault and, even if it was, it doesn't excuse developing hardware that doesn't work with in-spec USB-C power supplies and depends on inherently fragile storage media.
This is anecdata from my part, but I’ve got eight or 10 Pis running (Flightaware/ADSBexchange, PiHole/Influx/Grafana/Wireguard, a couple of Octoprint, Home Assistant - with a relay HAT for triggering dampers, Showmewebcam, and a handful of other things). Once I switched to good power supplies and good SDHC cards, my problems went away. My most heavily loaded machine is the PiHole machine which also has influx running and writing to the SDHC card - it’s probably a ticking time bomb, but it’ll celebrate it’s fourth birthday on the same card in two months.