Yeah, it’s like pretty much all other scotch guard type products, or even exterior ceramic coating type products. They ALL wear out over time and need re-application. My concern would be the expense of that particular product v how well it actually protects the seating v then reapplying in 5 years.
That said, hopefully some other members can speak up if they have experience with the interior coating Vantage coating product, or its reapplication.
I will say this, for most people, the Semtex seats clean up really well. Some types of stains and environments are worse than others, and of course seat color can factor into that too (whether things stand out or blend in).