Do extracurriculars matter for grad school admissions?

It matters, but not in the way it mattered for college.

When my older daughter applied to grad school it helped that she had experience in the field she was applying to.

My younger daughter just finished grad school apps. She needed volunteer experiences, shadowing, advocacy work, etc. Her application would be considered incomplete without these experiences.

I think the answer to your question is dependent upon the degree you are seeking and what the programs require.