To be fair I wouldn't be surprised if the cause of this is precisely the purity of GrapheneOS: given it lacks Google services and Firebase Cloud Messaging to ce

To be fair I wouldn't be surprised if the cause of this is precisely the purity of GrapheneOS: given it lacks Google services and Firebase Cloud Messaging to centralize app notifications through Google, the apps need to do frequent polling or keep an active connection to Facebook's infra to receive notifications. Same with Telegram, each has a slightly different polling mechanism when Google-powered push is not available (a common in phones without Google services), which is most likely way less power efficient.