A continuation of Kelly's transition into pop-punk, Mainstream Sellout was met with mixed reviews from critics.

[14][15] A 20-second teaser of a song was teased on Instagram prior to the album announcement: the post was captioned "Signed a deal; I got papercuts", which matched the lyrics in the clip.

[22] On March 14, 2022, Kelly revealed the album cover and the tracklist using a series of Dolce & Gabbana designed clothing items that featured the song titles.

[25] On March 16, 2022, after having performed "Maybe" during Emo Nite in Los Angeles,[26] Kelly released the track as the fourth single of the album.

The song features the lead vocalist, Oliver Sykes, of British rock band Bring Me the Horizon.

[38] In a positive review, NME described the album as "no complacent victory lap" from Tickets to My Downfall, praising the album for having "a relatable sense of angst" that will "continue to speak to the millions who see Machine Gun Kelly as the saviour of punk rock", concluding that "though it inevitably lacks the shock of the new that made Downfall so exciting...it seems that, like the pop-punk revival itself, Machine Gun Kelly won't run out of steam any time soon.

"[1] AllMusic noted that while the music was filled with "big, distorted guitars, simplistic but catchy hooks, and Barker's tight, snappy drumming", they found it to be not as good as Tickets to My Downfall, with it being "lighter on ideas and cohesion".

[2] Charles Aaron of Rolling Stone named the tracks "evolving, not-very-joyful noise" while opining "his buzzsaw-bubblegum can be entertaining.

[37] Helen Brown of The Independent called the album "dull", "formulaic", and "the kind of thing you'd expect to hear in the Vans outlet of your local shopping mall".

[43] Emily Swingle of Clash opined that the album was "a brash but ultimately shallow return" and that "it's a shame that Kelly couldn't release a follow-up equally as fresh and fluid", but did name "Sid & Nancy" and "Twin Flame" as standout tracks.

[44] Arielle Gordon of Pitchfork wrote that "the enfant terrible of the pop-rock revival wades deeper into the genre, coming back with even less than before" and that it "too often feels like a concept album about rock.