Personally I would say it supports long campaigns very well. The characters are pretty resilient if the players are not ridiculously gung-ho. Bennies are a great safety net and as the GM you can choose to be generous in handing those out.
Character development is pretty solid. The rank system means that characters tend to develop horizontally (gaining a broader range of abilities) as well as vertically (building up their powers) and that is one of the things which helps flatten the power curve.
A non-obvious benefit for longer term gaming is that the characters are more broadly and flexibly capable than is common in D&D. That comes in large part from the Wild Dice but also the flexibility of the skill system. When I play D&D I tend to play Bards since I like flexible characters. In Savage Worlds all character are more flexible so that limitation is non-existent.
Character development is pretty solid. The rank system means that characters tend to develop horizontally (gaining a broader range of abilities) as well as vertically (building up their powers) and that is one of the things which helps flatten the power curve.
A non-obvious benefit for longer term gaming is that the characters are more broadly and flexibly capable than is common in D&D. That comes in large part from the Wild Dice but also the flexibility of the skill system. When I play D&D I tend to play Bards since I like flexible characters. In Savage Worlds all character are more flexible so that limitation is non-existent.