1. The Republican gerrymandering is overrated. A bigger problem us the fact that geographic location is doing more to hurt the Dems. Remember, the Republican Party won the popular vote for the House in 2016.
2. A bad economy probably makes Pelosi speaker again.
I think too often gerrymandering is unfairly blamed
entirely for the current conditions, but it certainly has cost Democrats a number of seats. Had 2010 been more balanced in terms of redistricting, Democrats would probably consistently hold the same number of seats as they did in the 90s - early 2000s, in addition to there being more overall opportunities.
I believe it was also Sabato who laid out an interesting case that incumbency has, arguably, a larger negative effect. I still think it might be a net benefit to our system of government if we tried to disincentivize or outright prohibit politicians from turning their districts into long-term careers.