The first buff was added to make it more reliable to freeze versatile heroes.
The second buff was added to make her freeze enemies easier without having someone else body block you. Not to mention that it can help freeze multiple enemies faster in her ultimate.
These buffs did not made her a lot more viable, but I don’t think they can buff it more without making it too oppressive. It’s an unfun ability for others after all.
I do agree with you that her ultimate should be addressed. It’s the most unreliable ability in her entire kit. I would love to see it’s cast time significantly decreased.
Increasing her fire rate would help a lot as well. Having a hero who’s primary role is CC will always be subpar to DPS’ers who can just kill enemies. But we have to be careful that she will not replace McCree’s and Hanzo’s role. If her fire rate is increased, then her damage might need to be adjusted as well.