To study the heavy-ion-induced reactions, particularly complete and incomplete fusion, the excitation functions for ${}^{16}$O$+{}^{165}$Ho interactions at energies $\ensuremath{\approx}$73--105 MeV have been measured using a well-established activation technique. The excitation functions have been compared with the predictions of the statistical model code pace4. The comparison advises that the formation of $xn$ and $pxn$ channels is governed only via complete fusion processes. Even after correction for precursor contribution, a significant enhancement in the production of $\ensuremath{\alpha}$-emitting channels may be attributed to incomplete fusion contribution. Furthermore, in order to understand incomplete fusion reactions in a more conclusive way, the incomplete fusion fraction has been analyzed with the existing data for ${}^{12}$C and ${}^{20}$Ne beams on the same target (${}^{165}$Ho) where a strong projectile structure effect has been observed, which correlates incomplete fusion reaction dynamics with the $\ensuremath{\alpha}$-$Q$ value of the projectile.