Is supplicating for the deceased sufficient if there is no one left to visit them in their grave, and do they feel the supplications of their family from afar?

Filial piety towards parents after their death is fulfilled by supplicating for them, giving charity on their behalf, fulfilling their pledges, maintaining kinship ties that are only maintained through them, and honoring their friends. As for the deceased's awareness of the supplication of someone distant, there are no explicit texts concerning it.