There's lots of indie games that get tons of updates, too. Minecraft is the big one in this space that kinda defined the model, Factorio is one of them too. Dwarf Fortress has had regular updates since 2006.
Get a playable version of the core game into Early Access for a low price, start releasing updates. Your player base provides feedback on the game as it evolves, free beta testing, and growing word-of-mouth promotion. Maybe even ideas for entire systems, especially if you have mod support. Eventually you expand it to have all the stuff that was in your original vision, and you bump the price up for the 1.0 release. Port it to consoles, decide if you want to keep on adding new content to make it the game you barely dared to dream it could be, or move on to the next project.
There's still people who keep a game quiet until they can release 1.0, but there's a lot of small games out there that get their stuff out in public as soon as possible.
Similarly, a lot of games built with Valve's Source engine get continual updates even today - a decade or more after release - specifically because Source gets updates and therefore so do the games built on it. It's interesting to see updates come in for Half Life 2: Deathmatch even though absolutely nothing player-facing has changed (to my knowledge) since the 00's.
Get a playable version of the core game into Early Access for a low price, start releasing updates. Your player base provides feedback on the game as it evolves, free beta testing, and growing word-of-mouth promotion. Maybe even ideas for entire systems, especially if you have mod support. Eventually you expand it to have all the stuff that was in your original vision, and you bump the price up for the 1.0 release. Port it to consoles, decide if you want to keep on adding new content to make it the game you barely dared to dream it could be, or move on to the next project.
There's still people who keep a game quiet until they can release 1.0, but there's a lot of small games out there that get their stuff out in public as soon as possible.