Gravitational self-force theory and the effective-one-body formalism are two different approaches to the two-body problem in general relativity, both suited to describe black hole binary evolutions, but natively pertaining to certain domains of validity. In this talk, I will present a comparison between waveforms from intermediate-mass-ratio nonspinning quasi-circular binaries evaluated with the two aforementioned approaches, locating the region of largest agreement and paving the way for accurate waveform modeling for third-generation detectors.