The prospects for growth are better than ever. GrapheneOS by installer download stats looks to have approximately a quarter of a million users, and the new Motorola partnership should cause that to increase significantly.
If nothing else, it will be a major OEM shipping a non-customer-hostile mobile OS officially for the first time in ages, and Motorola's reach is significant: https://www.androidpolice.com/motorola-razr-drives-foldable-...