"NME"s Sam Moore complimented the song's R&B production, but dismissed the lyrics, which he termed as "failed expectations". He opined that the song's producers opted for "minimalism with their choice of instrumentation, melding airy keys with pop-trap beats with an evident view of creating something as universal as the likes of 'Hotline Bling' and Childish Gambino's 'Feels Like Summer'". Moore further wrote that Bieber's layered vocals and harmonies are "able to glide along rather effortlessly—it's just a shame he doesn't have more to say with them" and that Bieber's embrace of R&B "isn't a complete turn-off". "Pitchfork"s Eric Torres criticized the song for being "shamelessly engineered for the truncated attention span of TikTok" and "a bloodless shell of an R&B song crippled by asinine lyrics and a tired, syncopated backdrop". He further wrote that the song "plateaus as soon as it starts, never inching past the toddler-like repetition of 'yummy-yum' in its chorus". Brad Callas of "Complex" magazine listed "Yummy" amongst the best new music of the week and said Bieber's "pivot back to R&B is refreshing for those who were fans of his slept-on 2013 project, "Journals"". Callas further remarked that the "silky vocals" is at times reminiscent of Bieber's 2016 collaboration with Post Malone, "Deja Vu".