Changing career sectors?

I've only interned and worked for nonprofits. But, here lately, I've thought more about how I might benefit from applying for jobs in the for-profit sector. I also recently caught up with a mentor who is my former supervisor, and she told me that having a diversity of experience across sectors and industries was so beneficial to her. What do y'all think about this perspective? Is it more valuable to have that diversity of experiences, or to stick within one sector and have years of experience there specifically?