It also means more people can play on more hardware, it typically focuses the experience, it makes the interactive elements more visually distinguishable from the background graphics, it's cheaper/faster to produce so less incentive to bloat with MTX to recoup massive investments, the scope is smaller so can be better aligned with a singular cohesive artistic vision, and the limited graphics encourages stylisation and artistic decisions when 'photo real' becomes not an option to target.
Also you don't need to wait 10+ years for a game, just to receive a bloated mess where you only engage with 20% of the content yet had to wait for 100% of the development time, since at that point the investment demands it has to appeal to every possible consumer, only to still get a buggy unfinished release due to the massive scope. /rant. Anyway, indies are great and i love short games too.