Early 20s “sound”?

Billie Eilish and her "bedroom pop" sound is pretty much the defining sound of this era for pop music. Hip-hop hasn't changed much since 2015-16.

Music right now is annoyingly stagnant due to the pandemic. No concerts/shows/nightlife actually does affect this.

Yeah trap is definitely moving away from the aggressive and purposely overproduced beats of the late 10s and has become more lyrical and melodic like you said. It sounds a lot more fun to me honestly and it’s definitely a change in tone as late 10s trap was pretty gritty. The days of mumble rappers making songs about popping xannys and drinking lean seems to be over for the most part

Don't forget these too:

Would Driver's License count? I feel like the bedroom pop aesthetic make's it different from what was popular in the 2010s despite her Lorde-esque vocals.

And y'all said nothing was changing. 

I wouldn’t count Drivers License. I agree, it sounds like something that could’ve come out in 2016-17. There’s still a few songs that could fit that time frame

I'm also not surprised because years "0" and "1" has previous decade remnants. We're only in 2021 and the 2020s barely started. I believe that we're hardly removed from the late 2010s, despite the new exciting cutting edge trends popping up and or becoming noticeable. Pandemic aside, the late 2010s feel like yesterday.

Year "0" is pretty much identical to the late part of the previous decade, specifically years "8" and "9." 1980, 2000 and maybe 2020 follow that. 2010 and maybe 1990 are exceptions. 2010 had late 2000s influences. I remember hearing late 2000s music on the radio in 2010. At the time, I thought it sounded current. I'm sure 1990 had late 1980s influences. 

Year "1" is a transitional year where it has previous decade remnants, but also current decade trends become more apparent. By late year "1" or early year "2," we enter the decade's prime with the new sound overtaking the old sound. The old sound and previous decade's influences linger in year "2," but are gone sometime in year "3" when a decade forms their identity separate from the previous decade. Around year "3" is when we enter a decade's core and previous decades influences are obsolete. Years "4" and "5" are the peak of the decade. 

The new sounds we hear now will overpower the older sounding songs by 2022 or possibly late 2021. However we may still hear older sounding songs in 2022. 2023 will most likely have no trace of the older sounding songs and that'll be when the core 2020s begin with the 2020s forming their identity separate from the 2010s. Late 2010s influences will be extinct by sometime in 2023.