Yes, I meant that the seal eventually leaks and I get rainwater coming in and running down the inside of the glass or at the corners of the windshield.
Crappy operators tend so save on the quality of the adhesive they use, that saves a couple of bucks and looks just the same right after you leave their place of work but it comes back to haunt you in the long run. A 'proper' operator will use the exact same glue as the manufacturer originally used. Another common error is to not properly glean the surfaces the glue will have to bond to both mechanically and from various residue. This can cause the glue simply not to stick at all. The first is greed, the second is usually crappy instruction. The guy I know has worked for manufacturers on mass windshield replacements, so he has done thousands according to manufacturer spec and that makes a big difference in workmanship, but he says that there is no guarantee that a dealer will do a better job, there is the guarantee that if the dealer fucks up you usually get your next replacement for free and some of those window replacement businesses are 'fly by night', the worse the quality the bigger the chance that you will need them to honor their warranty, but also the bigger the chance that they will no longer exist. Insurance companies sometimes work with a bunch of preferred installers. Here in NL besides by friend I've also had reasonably good experiences with Carglass, not all without trouble but they want to stay in business. Over the course of now close to 40 years of driving I've lost a whole stack of windshields, especially near construction zones but the last couple of years have actually been pretty good. I probably shouldn't jinx it though :)