Replacing bars and stem every 5000km?

On the Rose site they warn the customer to replace these items every two years or 5000km. Is this really necessary if the bike hasn't been crashed?
Pegoretti
Colnago
Cervelo
Campagnolo
Colnago
Cervelo
Campagnolo
0
Posts
Damage or 3 -5 years depending on use.
Tyres last 5000km on average and they're made of soft rubber that's in contact with the tarmac all the time.
I know a few people who've snapped handlebars - almost all of them fixed riders going up hills. Never heard of a stem failure amongst anyone I know.
Clearly a hefty crash is going to be of concern, but periodic inspection (when you do your bar tape etc.) is more than enough for most of us.
Fixed riders should pay a little more attention to their bars for sure (especially if they are riding very long gears regularly).
Nittos on my Audax bike are somewhere around 30000km old and still look amazing. I won't worry overly.