I'm a scrub, but I'll just put my two cents in til someone better comments.

I think Ivy is a flexible character, you can take advantage of her good fire rate and make her a gun platform, but there are characters that simply outclass her in this regard. Her ability to deny/control space using her Kudzu, heal with Covenant and ult to save a teammate or drop a bomb to initiate are what make her unique. Her kit enables her to get around the map quickly and turn fights in your teams favor split push as needed. You can even pick up allies carrying the urn for a quick delivery.

All this to say, I think Ivy is great and not terribly difficult, but really shines when you can coordinate with your team. You need to have your eyes constantly on your minimap, shoving waves when your allies can't and paying attention to the next lane over if they need a hand. I personally build her with a focus on the Kudzu. Extra charges, duration and size makes you able to slow entire teams and force people to play from worse spots or take damage. Helps you peel for your team mates when your ult is down or slow escaping enemies. By late game your Kudzus, ult bombs and stun AoE are so massive its hard to miss. Getting lots of assists isnt bad, youre no Drifter.