It depends on how much Nioh you crave I guess? Like, Nioh 2 just kind of improves on every aspect, honestly. At the same time, it's often called Nioh 1.5 in that it's essentially the same overall game but with more levels, more enemies, more weapons, etc. but with a few new mechanics and various QoL improvements.
If you were getting fatigued by 1, I would say just skip ahead and jump straight into 2. If you had a blast with 1, and do plan on playing 2 regardless, then just finish it normally.
Sod it, I'll jump straight into 2. I enjoyed Nioh but I just fell off it, I'm too impatient to struggle to get back into it now. Thanks for the info!