If one were to recall and pinpoint a specific musical style to have really blown up in the 2010s, it would without doubt have to go to electronic dance music. The scene blew up to such large proportions that it quickly became very oversaturated -- to the point where the term "EDM" became derogatory and had negative connotations to it. During the latter years of the 2000s, particular elements of house, techno, trance increasingly crept into pop music that at the turn of the decade, the genre became part of the "mainstream" sound. Top 40 pop acts of the time like Black Eyed Peas, Usher, Britney Spears, Akon, Lady Gaga and Katy Perry incorporated electronic elements to their musical aesthetic and eventually, veteran electronic musicians like David Guetta, Armin Van Buuren, Tiesto, and Calvin Harris -- and relative newcomers at the time like Skrillex, Deadmau5, and Avicii -- joined them with chart-topping hits as well. House and trance music were staples at parties, raves re-emerged and became trendier than ever, and fist-pumping became one of the most prominently emulated dance moves. While electro and progressive house were the most popular forms of electronic music at the time, there was another "new" emerging sound that simultaneously came about -- dubstep.
Taylor Swift's "I Knew You Were Trouble" (2012) was heavily inspired by dubstep
At least, that might be what the casual listeners assume. Those who know their music history (or have an affinity for the UK underground) would be well-aware that the genre and term have existed for quite some time before that. We won't go into too much detail about dubstep's conception, but it's generally accepted that the genre emerged in the late '90s out of South London, inspired by other prominent UK sounds like garage, drum and bass, jungle, dub and reggae. However, if you had thought that dubstep has its origins in the early 2010s, you're not entirely wrong. In the same way how the sound of house music evolved drastically after it merged with mainstream pop music, the popularized style of dubstep has very little sonic resemblance to its original form.
Example of UK dubstep: Skream's "Midnight Request Line" (2005)
The genre heavily departed from dub and UK garage, borrowing heavily from more common styles like R&B, hip-hop, pop, rock, metal and other electronic music. By the start of this decade, dubstep gained significant popularity in the U.S. market and its "Americanized" form was dubbed as "brostep," with U.S. producer Skrillex unofficially becoming the posterboy for the movement, with other prominent artists (including UK ones) like Rusko, Caspa, Flux Pavillion, Doctor P, Datsik, Excision and more cosigning the sound. "Brostep" -- dubbed by dubstep purists because of the genre's popularity with young teenage males -- was an aggressive variant of the UK-style dubstep. The genre's signature bass-driven aesthetic transformed to distorted midrange sound which played a similar role as a guitar's in metal music. The groove and bounce evoked by dubstep got replaced with brostep's much more aggressive headbanging and fist-pumping. (For the rest of this piece, we will refer to "Americanized dubstep" as "brostep" to differenciate it from dubstep's original form; no offense is intended by the usage of the term.)
Example of "brostep": Flux Pavillion's "I Can't Stop" (2010)
In a recent conversation with Minnesota newspaper Star Tribune, California producer Bassnectar addressed his dislike for the term "electronic music," claiming that "it's not a thing anymore" and that the whole world is "electronic," hence making the term redundant and invalid. He proceeded to comment on the current state of dubstep, saying that it is "a thing of the past," and is replaced by a new wave of "shoegazer, hipster brand of dance music." While many of the things he shared were understandable, his argument only partially addressed the overall issue. Kelowna-based producer Excision decided to expand on the topic and give his opinion of what really is happening with dubstep. He clarified that many people listened to or identified with the genre because, at the time, it was the popular or "cool" thing to do. He believes that the majority of that particular fanbase has moved to the next "hipster trend," and those who remained fans were the ones who "are there for the music." From the perspective of someone outside looking in, dubstep may have "fell off the map" based on ticket and track sales, but the reverse has been happening to him; fans have steadily increased every year and continue to do so. Instead of trend-followers, his crowd has been "refined to music lovers," hence there is a "reduction in quantity, and an increase in quality."
What Excision shared is very valid for his case, but the phenomenon he describes is not limited to dubstep but also any other genres that blows up as trends and fadeS away from the mainstream eye. Moreover, both Bassnectar and Excision are referring to the decline of brostep as a fad rather than dubstep as a whole. Interestingly -- although brostep seems to be a bastardization of the original dubstep to certain purists -- for producers like Excision who built their sound on brostep, the genre isn't a gimmick nor is it a trend. These producers did not make underground dubstep before this and "sell out" to get to where they are. They became passionate about an emerging genre that purists have hated on and given a bad name to, and continued to develop and evolve that sound into something entirely different.
In conclusion -- no, dubstep is not dead. The more accurate assumption is that dubstep in its trendiest form (brostep) is no longer the "cool" or "hip" style it once was, and has been replaced by other trending styles. However, there are those who keep the brostep sound alive and have built a loyal fanbase who listens to the genre because they love how it sounds. The same can also be said for UK dubstep, because technically, that sound has never reached mainstream popularity, and therefore, cannot "fall off" or "die."