ive read everything you said, but just quoted the tldr because the quote will take too long, just do very simple devlog videos with mild editing of whats going on in the game. be entertaining, make people look at you and the game something different. something they think they wanna play
as ive said, the dude named goodgis has got a team of developers and alot of people dropping in money just to help him better quality stuff in less than a year because they're entertaining and make just how gamedevs go on about their day and games videos.
i dont have much to say but like, try making simple videos, get some hype goin in the games name.
subscriptions? idk give it a try, people will complain yeah sure. but yk, try. subscriptions give players cool looking stuff idk examples for
donations? PROBABLY wont work, but hey. just try. drop it in in the login screen and put "everything helps

cosmetics:add community cosmetic suggestions like how madam got the colorizer in game. maybe a cosmetic set pack that changes every month? daily emerald shop rotation that gives out random purchasables or something
cheap goofy features that just boost stuff you do in game, not in particular p2w. example, an item to make you climb ladders faster. a whole 20 ems/a dollar just to make you climb faster? thats my only example for payvault stuff, probably will suggest more but just try adding really simple dumb things to the payvault for a reasonable price
my words arent really well organized, but the simple things like subscriptions, donations and other simple things to add are worth the try. yeah theyll complain so eh
the thing that i think thats making you not get alot of money is trading, its a really cool feature, yeah. but trading also just kinda make people not buy stuff from the payvault, like how peopel are buying ems from other people and buying emeralds from other people instead of buying actual sutff from the payvault. there are major eliatopia bulk sellers selling ems/cash for cheap. like theres people selling 50 ems for a buck, so that makes the 20ems 1 dollar offer in the payvault rendering it kinda useless
the only thing i personally want from elia is devlogs, advertise it through a paid advertisement on yt and that video should be a really high quality edited video and it should bring people in, explain passively that you/the game needs money to survive, drop links below to donate or whatsoever.