The most cost efficient way to advertise our ideas

I have experience in advertisement on russian language social network vk.com some years ago.
The price was like about $1-$6 for 1000 views of your post, depending on the audience you target.
It was nice to get >1mln views and ~52k (79%) votes in support of the launch of an international superproject to fight aging spending about $2k on advertisement of the post. Several hundred people joined relevant life extension chats as a result of this advertisement. The full list of advertised posts is here (in russian).

However I struggle really much when I try to find similarly cost effective ways to advertise and involve people in english speaking websites/social networks. Help me.

As for Facebook, I see many drawbacks: (a) you can't finetune your advertisement really well (like choose members of which groups would see your advertisement or maybe only people who are members in 2+ groups from some list of groups) (b) their price is too large (c) Facebook messenger is not very convenient comparing to discord/telegram but you can't include invite links to other resources in advertisement (d) you can not advertise surveys which is really bad because surveys are a cost efficient way to get contacts of supporters and also give confidence that fb really shows those advertisements (e) strange policy, when after each change in the targeting of already approved ad, it is again sent to the moderation and sometimes it is blocked, although previously it was approved

Perhaps ads on YouTube can be better? Overall, let's understand all that together.