Replacing 15 year old veneers - How often do veneers debond after they are replaced?

Hello, I had veneers placed on my front two teeth 15 years ago. They are really holding up well but I want to get them replaced due to them being quite yellow compared to the rest of my natural teeth. I'm very nervous and scared to replace them because I see so many stories on the internet of veneers debonding after they are replaced. How often do veneers debond after they are replaced? I've had two consulatations and both dentist stated that my bite is good but I just don't want to run into problems by replacing these veneers as they have held up very well over the last 15 years with no issues at all. Thanks!