What do you mean stranded? If you mean standard ethernet cable, it's 8 solid wires. Putting a keystone block takes about 1-2 minutes (with a tool). I spend more time figuring out which wire goes where than the actual retermination.
https://en.wikipedia.org/wiki/Wire#Stranded
These are typical in pre-capped wires. While they allow more flexibility of the wire, their ends are hard (if not impossible) to change.
I dabble in electronics and I eliminate stranded wire whenever I find it. Some people love it but I find it really inconvenient.