With proper configuration, they shouldn’t fail that often. I upgraded to an i5 SFF PC a couple months ago, but prior to that, I ran my system on an RPi 3B for 18 months with a single SD card.
The two biggest culprits when it comes to early SD card failure in Home Assistant:
- Power supply: Make sure you are using a quality power supply for your RPi (i.e. not a cellphone charger).
- Recorder configuration: As I mentioned previously, making sure you are only recording what you absolutely need in the database will reduce SD card wear substantially. If you haven’t done so already, you may also want to explore moving from the default SQLite database to the MariaDB add-on. Here’s a great Community Guide on optimizing your recorder configuration: How to reduce your database size and extend the life of your SD card
If you have the money to spend and have addiitonal uses in mind for your system beyond Home Assistant, then by all means, go for the NUC. But if things were otherwise alright with your current system, try optimizing your SD card situation first and see if that lasts you awhile.