Case 1: Strong dollar. 1 USD = 1 EURO
Case 2: Weakened dollar. 1.5 Dollar = 1 EURO
If Microsoft sells licence for windows in Eu for say 10 Euros. In case 1, with strong dollar, Microsoft will earn 10 USD. In case 2, with weak dollar, Microsoft will make 15 USD. So profit for the company increases by depreciating the currency, but it has some adverse effects too.
If some company wants to lend, it has to lend more money, because dollar is weak now. so, banks will make interest on more money.
Currently the interest rates in US are around 1%. So, by weakening dollar, companies have to borrow more money and could earn more dollars in return (profits). Borrowing cheap and making more money/profits. Because dollar is weak.
If dollar is strong, they need to borrow less and make less profits.
The problem is, there will be more outflow from banks which are currently sitting on huge pile of cash. As companies are lending more and taking risk, in case of defaults, guess what happens. If everything goes fine, money circulation improves, and this improves GDP too. So, more tax income to Government.
As more cash is circulating in markets, there will be more inflation.
As currency weakens, people income wouldn't increase immediately. Most of retail employees are on minimum wages. guess what happens to them, who currently aren't able to make ends meet. with inflation and minimal or no wage increases. scary.