Is there a word or phrase for this? Company reputation and customer satisfaction

[tectonicplates]

Is there a word or phrase for when a company has a great reputation, it starts going downhill but people don't notice for a while because they still build the company in high regard, and it takes a few years for people to start saying actually, they're not that good any more? Like people buying stuff because of a reputation that's no longer valid and being disappointed by the result.

Trading on its Legacy reputation?

I use ‘trading on past glory’. Thornton’s chocolate comes to mind, used to be seen as rather upmarket, M&S to a point. Lots of things have been cheapened, diluted or taken over and people haven’t quite noticed - Baileys- horrid now.

Are you talking about John Lewis by any chance? Ha

I thought John Lewis too....

We bought some Bailey's recently and I thought it was as good as always! Maybe I'll only decide it's rubbish once we've finished the bottle

I don't know the word but this has definitely happened to Marks and Spenser's clothes.. maybe 'doing a Marksies'?

resting on its laurels