> DAC cables are usually vastly more expensive then SFP+ optics and some multimode cable.
FS.com suggests 17€ for 10GBASE-SR, and 4€ for 1m of OM3, or ~40€ total, with three different components that could be a point of failure, in many weird and wonderful ways, vs ~10€ for a 1m 10G DAC, which is sold as a single unit and is replaced entirely in the event of a failure.
DAC is also lower latency at these short distances too, as you don’t need to convert electrical to optical and back again. It’s just end to end electrical.
Singlemode is not really required in a homelab setting because of distance, but DAC cables are more trouble then their worth in my opinion.