In the case of a potential lawsuit then it won’t look as though it was your negligence that caused the problem and as such you can avoid a law suit. The same engineers who worked no your maintenance can act as an elevator expert witness in a court of law, and if your elevator expert witness defends you by saying you took the necessary steps to maintain your elevator then you can avoid blame and financial punishment.
Regular elevator engineering will mean the elevator is also less likely to break down while you are not at serious risk (I.e. inside the elevator) meanwhile. A broken down elevator is of course a problem even if you are not inside it as it will mean you are unable to use it. If a lack of elevator engineering leaves you without your lift then you will have to take the stairs and will have no disabled access which can be a big problem if you have a disabled member of staff or a disabled client. Without an elevator for them to access your building this can be very embarrassing for your company and can reflect badly on your business. Meanwhile if you have received a large delivery, or some furniture, then without a working elevator you will be forced to get them up the stairs without your elevator.