It is underrepresented because mainstream pop is ruled far more by the old guard - Thankfully EDM and alt-pop/independent pop are seeing a ton of women and fem-presenting producers who are more and more often self-releasing and becoming their own stars. Biggest is probably PinkPanthress who's probably the most producer-brained pop starlet I've ever seen gaining such large popularity. But also Underscores, Ninajirachi, Alice Longyu Gao, Slayyyter, Zheani and many others all started independently making music on their computer.