There is no rules how many times one traces can go up and down with vias, ie, you space the traces and go under one trace, then up between the two traces, and over the next trace. That being said, if you laid it out well you shouldn’t need to, ie like microMerlin’s sketch. Vias have the advantage they are no extra work and cheaper, so they are more popular than jumpers on 2 sided PCBs.
Traces don’t have to be straight to other pins, you can weave them where ever. This what it took me to make this single sided.
microMerlin - Are the ratsnest between the pins of the MP1584EN supposed to be there.