yes, it is important, especially if you do monetiez a lot through ads.
1. it's important to maintain a relationship with your mediation partner, especially if you're also doing UA with them. this can lead to better performance both on the ua and monetization side. they want to keep you on their mediation so they have an incentive to make you happy over the long term
2. when talking with networks to try to optimize them, the ad networks are always asking for the same data : they want to understand a bit more about your waterfall, so as to see whether they can help you.
this is why some publishers share their waterfall data very often with the ad networks and it helps them understand how they could serve them better.
this is worth doing every once in a while, so as to get your account managers to give you floor recommendations.
while this is mostly done through simple CSV exports, some bigger publishers even have dashboards they share with ad networks with their waterfall data in real time, so that network's account managers can proactively analyze whether they can recommend them to add some floors given what their competition is doing.