We’re not going to speak for all the service garages but there are technicians who genuinely care about your safety and honest about what you really need to do to keep your car at proper condition.
First, what is the reason you go to get your car check anyways? Did you notice a strange sound when driving, some vibration, your break didn’t stop the car in time like you normally have it? There could be small and easy to fix problems or something with a chain of troubles.
Listen to your service advisor – ask detail questions – do your own research from reliable sources (car manufactures, part dealers, etc.) – and then make an educated decision.