If every town has 10 axes that do an extra 1d6 damage to elves, fey, and plant monsters, then are those axes special?
Yes, because while the town might have the ten, the party of PCs is unlikely to have more than one. What's more, that extra +1d6 damage will only come into effect infrequently, at which point the players get the "cool!" moment as they realise the extra effect.
A sword +1 gets written on the character sheet, added to the two appropriate boxes, and never thought about again.
Rather than trying to find some way to make the sword +1 special again the DM would be far better served to give out more interesting treasures. That way, you're not fighting against the inherent cynicism of people who have been playing for decades and have done all this before a dozen times.
Well, that or always play with newbie players for whom this is all shiny and new.
(And, actually, better still would be to simply remove the sword +1 from the game entirely - the treasure that is found should give the +1
and the +1d6 vs elves etc. Or +1
and occasional fire damage, or whatever. So that the players aren't disappointed that their +1d6 damage sword isn't the more utilitarian +1 sword instead,
and you get the ongoing "cool!" moments. Or, in 3e terms, the "Big Six" basically shouldn't exist as standalone items.)