Virtually every nonprofit organization needs to write grant proposals.
Which means that someone in your organization will be tasked with writing proposals, in addition to their regular work, or may be required to write them full time.
Researching and writing grants takes time and requires one to sharpen their research and writing skills.
You may be fortunate to have an experienced grant writer on staff.
But for many nonprofits that is not the case, and it might make sense to hire a grant writing consultant.