Tesla is getting crushed in China, its most important market outside the United States and one that it had dominated for years.

When Liu Jie, 32, decided to buy an electric car in October, Tesla was one of her top choices. But after test-driving a few Chinese cars, she went with a sports sedan from Xiaomi, a consumer gadget maker better known for its smartphones, kettles and robot vacuums.

“Xiaomi is more fashionable,” Ms. Liu said last week in Beijing. “Tesla, for me, it’s a little bit normal. You can see the Tesla Model Y everywhere.”

It’s not personal, buyers said. Tesla is still considered a top brand, and Elon Musk, Tesla’s chief executive, is admired in China. Beijing rolled out the red carpet when he broke ground on the company’s first overseas factory in Shanghai. Mr. Musk is credited with igniting China’s local electric vehicle industry.

But now that market is a blood bath of competition from Chinese rivals. Chinese drivers that once flocked to Tesla are turning more and more to local brands that offer more efficient cars with better technology, sometimes at half the price.

Tesla’s biggest rival, the electric car giant BYD, sold 481,318 cars in the first two months of this year, over three quarters more than it did over the same period last year. Tesla sold 60,480 vehicles in the first two months of the year, a drop of 14 percent from last year.

Tesla’s sales in China are plunging as the carmaker faces criticism over Mr. Musk’s role as an aide to President Trump in charge of cutting federal spending. Tesla lost about a quarter of its value over the past month as investors shunned the stock.

The threat that BYD poses Tesla in China has been building for years. BYD has sold around one million more cars each year for the past three years. The popularity of BYD has been driven in part by the fact that its cars are cheaper. It has helped that local governments sometimes steer business in the company’s direction.

But a property crisis and a broadly slowing consumer economy have hit households and badly dented people’s appetite to shop, making it hard for all carmakers. Things have become so bad that the government began offering subsidies a year ago for consumers to trade in their old cars. The government increased the incentives last week. Domestic companies have benefited from the subsidies, but so has Tesla.

Even amid the economic slowdown, there is still a market for luxury cars, for those who can afford them. Ms. Liu, who had a budget of around $41,000, said Tesla would have been an affordable luxury option compared with the $41,305 Xiaomi SU7 Max that she bought. And while Tesla offers a five-year zero-interest loan, Xiaomi does not offer any financing.

Many Chinese drivers are also willing to pay more for advanced technology like self-driving, an area in which Tesla has lagged because the government has delayed the company’s introduction of similar or better technology.

But Tesla faces another problem: demand. Sales are slowing for all cars in China.

The policies aimed at replacing gas guzzlers with electric vehicles have helped. In cities like Shanghai and Beijing, car owners can trade in older cars for a new one and get a nearly $2,100 subsidy. In some Tesla dealerships, employees have created a wall with photos of the cars that buyers have traded in — they range from Porsches to Mercedeses and even the occasional Chinese car.

But trading in an old car for a new one is usually a one-time thing.

For many dealers, it is getting harder to sell any car. “It was OK two years ago, but now the market is saturated,” said Chen Jiaming, a salesperson at an FAW-Volkswagen dealership in Shanghai, a collaboration of the Volkswagen Group with the state-owned FAW Group.

Mr. Chen works out of the “New Energy Vehicle Block,” in the basement of a mall near Shanghai’s Zhongshan Park that was converted from a food court three years ago when electric vehicles first took off in China.

Some of the one dozen dealerships in the basement of the mall have already left, the lights inside were turned off on a recent weekday. A row of claw machines lit up another empty space. In order to keep the FAW-VW dealership from closing, the mall gave it seven months of free rent, Mr. Chen said.

“I think Tesla’s competitiveness in China will only last for the next two or three years at most,” said Mr. Chen, who owns a BYD. Tesla’s driving technology is no longer cutting edge compared with local rivals, he added.

After years of lobbying the government, Tesla was finally allowed to offer a version of its Autopilot technology to Chinese drivers last month. The feature is a step below the full self-driving feature that Tesla drivers in the United States can use. Drivers who want access to the necessary software update in China have to pay an additional $8,800.

Younger buyers prefer Chinese brands, said Xia Lifang, an employee working at the nearby dealership for Arcfox, a Chinese electric carmaker. Tesla and BYD remain the most trusted brands in China, she said, but people born in the 1990s and 2000s are more open to trying new brands.

“Our car looks better than Tesla,” Ms. Xia said with a smile.

She added: “You could buy two of our cars for the price of one Tesla.”

Li You contributed research.