Is giving advice through social media beneficial, and is its giver rewarded for it, regardless of whether the advice is heeded or not?

Allah does not let the reward of one who calls to Him be lost. Allah the Almighty said: (And who is better in speech than one who invites to Allah). Da‘wah (calling to Islam) is not limited to direct speech; rather, it includes authored books and writing on social media. Whoever conveys Allah's message and offers sincere advice will be rewarded, whether or not the advised person acts upon the advice, and their reward is due from Allah. Whoever benefits from their advice will receive a reward similar to theirs, for the Prophet, peace and blessings be upon him, said: "Whoever calls to guidance will have a reward like that of those who follow him, without that diminishing their rewards in the least." So, let the one who calls to Allah be keen to utilize these modern means to spread good.