What kind of workload do you have where there are enough writes that a 1+ DWPD SSD isn't viable but the performance of a 10k RPM hard drive is adequate?
It would have to be a highly sequential workload for hard drive performance to not be a problem, but that means it's also a workload that's well-suited for QLC SSDs that are cheaper per GB up front and draw less than half the power and are faster in every way. If your worries about write endurance are at all realistic, you must be averaging upwards of 50MB/s of writes over the entire lifespan of the drive, meaning your hard drives are spending at least 20% of their service life actively writing data.
It would have to be a highly sequential workload for hard drive performance to not be a problem, but that means it's also a workload that's well-suited for QLC SSDs that are cheaper per GB up front and draw less than half the power and are faster in every way. If your worries about write endurance are at all realistic, you must be averaging upwards of 50MB/s of writes over the entire lifespan of the drive, meaning your hard drives are spending at least 20% of their service life actively writing data.