  Stripped-envelope supernovae (Types IIb, Ib, and Ic) that show little or no
hydrogen comprise roughly one-third of the observed explosions of massive
stars. Their origin and the evolution of their progenitors are not yet fully
understood. Very massive single stars stripped by their own winds ($\gtrsim
25-30 M_{\odot}$ at solar metallicity) are considered viable progenitors of
these events. However, recent 1D core-collapse simulations show that some
massive stars may collapse directly into black holes after a failed explosion,
with a weak or no visible transient. In this letter, we estimate the effect of
direct collapse into a black hole on the rates of stripped-envelope supernovae
that arise from single stars. For this, we compute single-star MESA models at
solar metallicity and map their final state to their core-collapse outcome
following prescriptions commonly used in population synthesis. According to our
models, no single stars that have lost their entire hydrogen-rich envelope are
able to explode, and only a fraction of progenitors left with a thin hydrogen
envelope do (IIb progenitor candidates), unless we use a prescription that
takes the effect of turbulence into account or invoke increased wind mass-loss
rates. This result increases the existing tension between the single-star
paradigm to explain most stripped-envelope supernovae and their observed rates
and properties. At face value, our results point toward an even higher
contribution of binary progenitors to stripped-envelope supernovae.
Alternatively, they may suggest inconsistencies in the common practice of
mapping different stellar models to core-collapse outcomes and/or higher
overall mass loss in massive stars.
