I hear this AND it gets said like it is a threat or a bad thing.
People leave because:
Okay, See ya. It was fun to know you and I wish you luck. Steem isn't for everyone. This community is voluntary there is no reason to expect everyone to stay and like it here.
In my early days on SteemIt I was also quite focused on User Retention, but in my past career people paid to be on our website, not the other way around. I've realized a focus on User Retention doesn't apply here.
There are plenty of creative and smart people here, they are figuring out how to get visibility and earn and they are adjusting their expectations. I watch new minnows come in, ask some questions, get frustrated and then figure out how to make a space for themselves. This is a decentralised platform with no leadership and 1000 people who think they are the only one who truly understands what Steem it is "supposed to be". It's messy, it isn't for everyone. That is okay.
It isn't up to me to say who should stay on Steem and who shouldn't, but it has become clear to me that not everyone will be able to handle it in the current form. Maybe some of them will come back when we have other front-ends and communities. Why would we want to retain someone who is triggered by Memes or so focused on what others earn they can't enjoy creating their own content. That seems cruel.

Communities and SMTs will likely help to create a community that reflects your values, but not everyone is going to do well in the current situation.
SteemIt isn't for everyone
It makes more sense if:
There are thousands of examples, but it isn't a fit for everyone, consider your investment and content goals and carry on as it makes sense to you.
Proceed... If you think you should.
PS Quit comparing your earnings to those on the Trending page and remind yourself what you were earning before you got here.