Darren Woods spent a year preparing an ambitious plan to return Exxon Mobil Corp. to glory.

Struggling with laryngitis, the oil giant’s chief executive stepped before a ballroom full of analysts and investors at the New York Stock Exchange in March and unveiled a strategy to spend more than $230 billion to double profits and pump an additional one million barrels a day of oil and gas.

As Mr. Woods walked away afterward and peered at his phone, he received an unwelcome surprise. Shareholders didn’t buy it. “Our stock is down 3%,” he said to another executive, looking exasperated.

Exxon faces a number of challenges, including investigations of its accounting and tax practices as well as lawsuits by cities and states seeking funds to pay for the effects of climate change. Its biggest problem is one the giant has seldom faced in its 148-year history: It isn’t making as much money as it used to.

Under former CEO Rex Tillerson, Exxon bet big hunting for oil in risky, expensive locales like the Russian Arctic. But as oil prices fell, those projects didn’t pay off the way Exxon had hoped. Now the $350 billion Irving, Texas, company is returning to its old ways: big, disciplined spending on prospects that make money at low oil prices.