Would you play a D&D campaign without leveling?

[Tallifer]

If we where playing in the sweet spot I see no reason to gain any levels.

Forsooth. Level 1 might not work. But in my current campaign, my players have been at 7th and 8th level for almost two years now with no complaints. There was a brief panic when the Witch was petrified and they thought the only way to unstone her was to get the Cleric to 9th level for Greater Restoration.