Don't tell the wealthiest country per capita in world history that - Switzerland. One of the few European nations that skated through the last decade almost entirely unscathed. They made a mistake in their attempt at currency debasement a while back, however they've almost always gone with a strong currency, and it has done wonders for their well-being. The median Swiss now earns twice what the median German does.
Also don't tell the US from 1820-1970 that. The strong dollar, backed by a gold standard, enabled the US to become the largest economy at warp speed.
A balanced to strong currency is ideal for a country. It provides increased purchasing power for consumers; it lures foreign capital; it keeps import costs low, including for commodities + producers; it keeps inflation from eroding the standard of living of the bottom 3/4 of citizens that can't hedge inflation; and it generates confidence for consumers, foreign investors, domestic investors, and businesses.