Hi there, just a 2 cents (great question).
I think that success is really the culmination of these circumstances. (the saying is: ‘‘everthing happens for a reason’’).
What is success to one is not to another (‘‘One man’s tr*sh is another,s man treasure’’/‘‘One man’s dream is another man’s nightmare’’). For me or you or anybody else, success could mean simply ‘making a game’ period, no revenue no fanfare, no nothing - no marketing, just don,t care at all. A big Success - to that person (only). But, for most, I think that is not really the kind of success they seek, because most devs (indie devs solo/2-3 team) hope that it Might become a sort of way to ‘live/make a living’; professinonally (I mean, not hobby), as such it means financial return, the game Has to sell or else, it’s not viable (at all). IT’s the ‘when the stars, planets and moons align themselves’ - you might be that 1; but, it is why (as others said) so many devs that do not find the kind of success most seek (which is, like games like Stardew Valley or Cuphead for example…that sold a zillion copies and made them a fortune that they can completely retire now if they want (when probably they are not much more than 50-60 years old, most game devs - most games devs are not that age and some are barely 20 (and that’s a good thing, new people in game industry)). But all this → competiont/oversaturation of game market…I think that is the Largest culprit of why 1 out of 14,000 devs aonly finds a sucess (such as becoming rich/famous and everything; well, maybe not that much but at least the game sells Well Enough to Live off of it)…because just ridiculously competitive, and platforms are Loaded to the Seams…so…I mean back in the 1990s, making a game was harder then…but there was Much less competition…that is major reason why some games ‘made then - If made today’ would flunk…because it just does not work anymore/does n’t impress anyone anymore and so these 90s game would not find success today - because a trillion
Other games are viying for wallet dollars of gamer (who is spoiled to no end - I include myself in that, as gamer…). more games the best, but more games makes it harder for devs to find an audience, because audience must choose (the cream of the crop at cheapest price), and so that leaves so many ‘eliminated’ - right from the start (ultra-seleciton ni the making). It’s why I asked a thread a few days ago : ‘‘So…a Unity Games Store?’’…not a single soul (ok 1) wrote…completely like…I was like…dmn…so I guess it does not matter - we could finally have Another place to seel our games…but no, not a peep just ‘you have to beon steam google or whatever UltraOversaturate place’ to sell your game. → failure highly likely, unless you haave a really great game and solid marketing, otherwise nearly sure your game will piled on by an avalanche of new daily games (like on Steam, 30 games come out everyday…that’s serious competition and sure some might say buy 99% of these new games are crp and so that is like 1 game out 30 that are actually worth considering…yet, makes no difference to you- you still have to face all This Extra Competition/extra ‘removed eyes from yuor game.’ going to another game(s) instead of yours). It’s also why you read game dev that says: ‘‘Fail fast…and restart’’…it’s true but…you know, many Can’t restart, failling you be your demise/over and out. Confiscius (I believe) said : ‘‘Success is not finding success the first time…it’s getting back up after falling (and then, finding success)’’, that is true success. So the ‘fail fast’ and move on; but, this is always in the optic ‘you can restart’ but sometimes you can’t - it’S final (and is what happens to devs with lots of money on the line and put 4 years to make their game and finds 0 success ‘despite doing everything right/doing marketing/trailer/etc…’;;maybe the audience did not like that genre (the game is not bad it just not wanted), nothing to do with your game speciifically; lucky successes often are unique or fill a niche ‘that was still empty/vacant’ before it got filled; then, it,s done. Too late; unless your really re-innovate on old thing.). It’s why it’s important to gauge the audience’s ‘wants’ / ‘needs’…you hope to make a game ‘that the audience did not know they even wanted’ (until you made it - kind of like Stardew Valley retro RPG SNES or Cuphead 1930s cartoones…who knew (until they made it). But that is wishful thinking/don’t put too much on that - rather, make the game you wish (with the audience pulse in mind of course, if you wish for it to sell more than less).
Just a 2c.
PS: I think devs that spend like 7 years on making a game is just too much/it’s crazy this much human life to make a video game - that could vert welll fllop the instant it’s sold so later (a very big risk, not worth it at this late point anymore). Never more than 5 years human time (for whatever artistic thing). Blockbuster games like CyberPink 2077 FPS games that took 7-10 years to be made, are not an example to follow anymore. I think 5 years is enough and you have to ‘stop’ at some point and say :‘finish(ed)’ even if it is not finished, it’s important becauese it forces you to limit your time in the longrun (years of making). OTherwise you could spend 20 years of your life on that magica game.