This is exactly it.
I work at a company that has used raspi's in hardware.
There are cheaper alternatives, but there are not better supported alternatives. The most expensive rPi is a rounding error in terms of engineering time. Why bother saving ~$30 if you have to spend $1k worth of engineering time to diagnose a compatibility issue on some less well documented board.
I looked into this for an industrial monitoring project. Its possible to configure the SD card as read only but kind of a pain to not be able to change anything.
This is purely dependent on what SD card you are using. If you use a random cheap SanDisk off of amazon it will probably corrupt and fail eventually. A SLC or pSLC industrial card has better ECC, write longevity and power recovery than a commodity card.
> The most expensive rPi is a rounding error in terms of engineering time.
* depending on volume.
For a couple hundred/thousand devices doing industrial automation yes.
For a million and up, it makes sense to pay an engineer 3 months to reduce the BOM by 10 cents.
Yes; not needing a full time Linux kernel developer and electrical engineer debugging your hardware and drivers because the SoC you're using was abandoned by the vendor 2 years after release is a big benefit.