Oh, I disagree with that. The bike fit “expert” is trying to upsell you the “invisible, undetectable clear coat” or the $2000 hammer. That is total bullshit. Sorry for the language. I have saddles that have lasted for many years. Koobi, a saddle manufacturer claims that their saddles last 400-600 hours, or roughly 10K miles. I personally have had a Sella San Marco that lasted for six years, and my Adamo saddles are on years four and five, respectively. As long as your saddle cover is still intact and there is no significant sag, you are good. Now, if there is damage to the rails or the plastic mold structure of the saddle, it doesn’t matter whether it has 5 or 50K miles on it, you’ll need to replace it.
Don’t get suckered into buying a new saddle if your saddle is not causing any problems. That being said, if you are having saddle-related problems, get a new saddle. I was having an issue caused by my saddle, which is why I switched to the Adamo.
Also, a tip with the Adamo is that you have to sit very far forward on it. I’m not sure why most of the saddle is actually there, as it encourages you to sit incorrectly on the saddle. I used to think that mine was too wide until I made an adjustment, sliding it backwards. Now, it’s perfect.