The Noise Reduction and Sharpening sliders might be the obvious go-to tools for optimizing high-ISO images, but these can easily leave you with soft, wishy-washy detail or exaggerated noise as you try to play one off against the other. In fact, there are better ways to get your high-ISO images looking smoother and sharper.
Detail sliders (Lightroom)
Lightroom Classic has two 'Detail' sliders. One is in the Sharpening section, where it adds definition but also some texture and granularity to fine detail. The other is in the Noise Reduction section. This slider offsets some of the detail softening effects of increased noise reduction.