Is buying an expensive smartwatch to benefit from some of its features considered extravagance, knowing that another watch without those features is available?

Extravagance and squandering differ based on individuals, their environments, their earnings, and their state of wealth or poverty. What may be considered extravagance for one person might not be for another. If the watch does not deplete your wealth, is suitable for someone like you, and is beneficial, then purchasing it is not squandering.