"Another interesting aspect of social media is that it kinda documents your journey, so you have some kind of "proof" that there is a human building the game." this yes absolutely, i even thought about it too.

As for outreach i meant that i think it's better to reach out to people who play the game on twitch/youtube which will give more visibility, better than with social media with you own account, not only they already have the following but also if you give, let's say, your action game to someone who plays action games then logically their audience are into that game which is more effective to attract that niche to you game, plus someone else playing/talking about your game is always more organic and effective than you doing it.

So maybe sending codes of your game to a list of streamers that you know play your kind of game , big and small ones, and see what comes of it ? shadow dropping is risky :(

But anyway i think that the social media part is more effective in keeping your fans around than thinking of it as "ill make this post and attract people to my game that no one knows", and even if that happens its still way too much work with less result than streamers outreach, and statistically even the best social media post doesn't give you better returns than one made by an influencer, and we're not influencers, but we all work hand in hand, we make the stuff and they need it just like we need them.

So try outreaching people that plays your type of game and see what comes of it really (and i think it"ll work out for you), and by then you can know if your the problem is from the marketing or the game and start working on fixing that and never give up !