Since For Rent My sims take way too long to finish tasks or initiate them.

@FairyPinkett Given that this isn't an issue specific to Residential Rental for you, when did you last do a clean folder?

Exit Sims 4 then drag your whole Sims 4 folder from Document > Electronic Arts to your desktop. Launch Sims 4 and reset your Options. Exit, then copy the contents of the Saves, Mods (but not resource.cfg, Screenshots, Tray, etc. into the new folders. See if that's helped during gameplay.