Even without the incremental GC it's manageable and it's just part of optimising the game. It depends on the game but you can often get down to 0 allocations per frame by making using of pooling and no alloc APIs in the engine.
You also have the tools to pause GC so if you're down to a low amount of allocation you can just disable the GC during latency sensitive gameplay and re-enable and collect on loading/pause or other blocking screens.
Obviously its more work than not having to deal with these issues but for game developers its probably a more familiar topic than working with the borrow checker and critically allows for quicker iteration and prototyping.
Finding the fun and time to market are top priority for games development.
