How turbulence affects accretion onto supermassive black holes

General-relativistic magnetohydrodynamic simulations resolve accretion and jet launching near supermassive black holes (SMBHs), but cosmological simulations lack the resolution to model these processes self-consistently. We use idealized simulations of low-power AGN jets to bridge this gap and study how interstellar medium (ISM) properties and jet-launching parameters regulate accretion and jet propagation. We find that turbulence in the ISM is essential for both jet launching and propagation. Without turbulence, cold gas cannot reach the Bondi radius, limiting jet power to 10^39 erg/s for a 10^6 solar mass SMBH. A turbulent, multiphase medium sustains higher accretion rates and enables jets to propagate to distances of 400 pc. Self-regulation of accretion is not achieved in turbulent environments unless the accretion efficiency is sufficiently high. Jet power depends on the gas density near the black hole, while the global ISM density has little effect on the maximum jet extent. Instead, the ISM Mach number plays a key role: supersonic turbulence produces dense filaments that intermittently boost jet power and low-density cavities that facilitate extended propagation, whereas subsonic or uniform media confine jets more efficiently despite relatively steady but low power. Finally, low accretion efficiencies do not lead to self-regulation, while increasing the jet opening angle promotes it without fully suppressing accretion.