Hardened valve seats - do they really matter?

I bet right now the people in this discussion thread are the last ones to ever rebuild any of this 60s 70s mopar stuff whatever we leave behind will be it. It doesnt matter if you put hardened seats in and it will "last forever" it will end up melted down in 20-30 years anyway...its truth there will be dwindling demand over the next few years...LS swap modern engines will be shoehorned into the bodies. Noone will rebuild or machine anything. I know its negative but its also reality.