Valentina3 said: "Schumer is in the Senate, not Congress. The lifting he is doing is differently felt than Pelosi, and more visibly so far since Senate's job is front-loaded with various confirmation hearings for the incoming President's nominees. Pelosi's only real challenge under Trump was the AHCA bill, and to a certain extent the ISP stuff which Democrats in general were not too thrilled to spend energy on. She still whipped all Dems (bar faux-Dems who're basically GOP) to vote against that bill. There's tax reform, new budget, and border wall bill coming up - let's see what she does with those.
There's also a confusing narrative about a House majority/minority leader's job as someone who decides direction of the party in terms of election resource allocation. The DNC as a whole is to blame for party's embarrassing loss, not Pelosi. She does share some blame, but not nearly enough to "go away". If anything, I'd like to see her make up for her mistakes by staying and fighting, using her experience and resources as only she can. You don't fire someone because they have too much experience.
As for younger, youthful leaders who can take over - Kristen G, Elizabeth Warren, Kamala Harris, Cory Booker, Ted Lieu, Keith Ellison, Adam Schiff (I can go on, but I'd say we can expect a future Presidential candidate in of any of these people). Granted, some of them have held office for quite sometime now, but they're all pretty vocal post-2016.
I think you're laboring under a large number of misconceptions, not the least of which is that the Senate is not part of Congress. As leader of the Democrats in the House, if you think she doesn't influence the DNC in how they support House races, I think you are very mistaken. More than anything else, your entire frame of reference about her performance seems to be roughly 4 months. Mine is 8 years. Time for her to go.