Could, should, would... and if the moon was made of cheese, we could have a stellar fondue. None of that is a fact!
Hypothetical: Itch COULD get their download function in order.
Fact: It IS NOT in order.
Hypothetical: If it WERE fixed, using it WOULD be viable.
Fact: Relying on itch downloads IS NOT viable.
Conclusion: IF and WHEN Itch gets off their butts and improves their downloads, and NOT ONE SECOND EARLIER, you can POLITELY SUGGEST a switch to using it.
So, why don't you go and pester the itch team to improve their broken app and site rather than spamming pointless replies that only serve to display your ignorance?