Hot water heaters typically don't last most then 20 years or so. AO Smith used to sell glass lines tanks that lasted longer, but were fragile. Areas with acidic water, like the west coast, tend to go quicker.
The new tankless heaters cost more, but don't waste energy heating up water over night.
A large house may need more than one tankless however, because you don't want temperature variation when someone is taking a shower and someone else wants to do laundry or dishes.