There was a lot of Gerrymanding (Pennsylvania, by their Leftist Supreme Court) and longstanding GOPe retirements (like Ros-Lehtinen).
Democrats won by a hair in most of these. Trump campaigned around the Senate, not the House.
Places like FL27 and CA48 disprove the notion the wealthy only care about tax cuts.
They also like their no-tarriffs to supply their warehouses and bring in their offshored manufactured goods, as well as their abundant cheap slave labor via massive unprecedented immigration (so that the US is 20% foreign born, sky high, totally extreme, next two largest immigration destinations Germany and Russia are below 5%)
Cutting back immigration from absolutely ridiculously extremely ultrahigh like it is today, back to high (5%) is gonna take a lot of education of the ignorant, who think we don't take in anywhere near enough people and should just throw the borders wide open and abolish ICE
Looks like both House and Senate will remain Republican at this point.