To be fair we do not know what kind of abuse the car went through. Another thing is quality of parts may be of another factor why the car creaks over duration of time.

Be fair 10 years is really a long time for rubber/ silicone/ PU parts to be in service.

Spraying oils/ chemicals is only a stop gap measure. Replacing is the only way to go. You have to remember crushed /worn with material loss/ cracked parts cannot be rejuvenated with any chemicals.

I am driving a 10 year old Myvi and a 43 year old Corolla. So i do know what kind of acceptable damage and wear level either car has with the age and driving that goes into it. Your 10 year old Honda would have same wear level on suspension as my Myvi. The myvi has creaking sound at the back when braking. And rattly under carriage when driving on bad roads. All are due to worn bushings that needs to be changed. I have sprayed WD silicone on these joints and it is only good for about a few weeks if it was not raining. I wish i have time to mount an action cam to the under carriage to prove my point. But get the car on a lift and manually shaking the suspension & control arms confirms the worn parts for play and creaks.

If you are still not happy that anyone can prove that the worn parts that needs replacing, then buy a new car.