I regularly see games with malware. Though I do not download them to check which malware is in it.
I made a thread about it.
https://itch.io/t/3512426/itch-is-not-a-safe-place-do-not-download-things
That being said, there are cases where there are false positives. But better be safe than sorry. Against some malware it helps to use sandboxing.
Even legit developers could get hacked and unknowingly upload malicous apps.
(This was of course malware.)