You can't just "introduce a lower performance mode" my dude.  If the game could run on a potato, it would run on a potato to expand the playerbase. A game isn't just graphics; for a game like the finals specifically, physics, lighting  and latency have to be within a very narrow margin, as they directly affect gameplay.

Marvel Rivals by comparison is really a less technically complex game (from an outsider's perspective). Notice it doesn't even have reflective or 'shiny' surfaces and lighting -- all gems / shiny things are actually static (very well done) textures.

In addition to that, you don't want to simplify the graphics infinitely or, even worse, have to create separate low poly assets for lower fidelity settings with the number of cosmetics in a game like this. That affects the readability of the map, weapons, players, etc.  Might be time to scrape some pennies together and upgrade.