The problems began 12 years ago, when a number of high-quality projects, and even the entire RTS genre, were destroyed due to a number of negative factors.
Because without expensive marketing, a project may not reach the target audience (hardcore gamers are a minority) and be overshadowed by more high-profile releases.
There were also factors of the boom in online projects, F2P, and piracy.
Because when a player has a certain amount of money and a choice between a premium release, a donation to an MMO\F2P project, or another type of entertainment (cinemas, etc.), only one person will get their money. With the piracy factor, a player can get a premium release for free, and someone else will get the money, where this option is not available.
RTS, more than other genres, began to rely on multiplayer and e-sports, and they got burned. Because the main audience played the single player, they had to rely on DRM, not the part of the game that was interesting to a minority of the audience.
Therefore, a significant part of the blame lies with the audience, which made the wrong choice at the time, thereby building a world where most of the money is generated by F2P games and microtransaction projects protected by online integrations.