They should get the same level of financing (donations) as Tor project at least. Some big organization like Open Technology Fund or NLnet should give them yearly grants.
900+ donors on github (https://grapheneos.org/donate#github) is not *too* bad, but likely not enough to cover a full salary.
900+ donors on github (https://grapheneos.org/donate#github) is not *too* bad, but likely not enough to cover a full salary.