Also, a weaker dollar contributes to inflation by making imported goods AND services more expensive.
In the absence of tariffs, a weaker dollar would have encouraged foreign demand that would compete with domestic demand, driving up domestic prices for domestically-produced items, but in our current case the tariffs have more than negated this effect.
Finally, a longer-term weakening trend in a currency, or a political policy of weakening one's own currency, causes investors to eventually demand higher real yields to offset their exposure to currency risk. High real yields act as a brake on the economy. Higher retail margins are required to exceed the cost/benefit ratio of the alternative to buying inventory: just buying bonds.