The way innovators erode a legacy company’s advantage is by attacking an area they aren’t worrying about. Usually, that’s cost (“Japanese cars”, x86 supercomputers), but sometimes it’s speed, power, or convenience (Amazon.com in the 90s). Car companies have had plenty of warning about cheap EVs, but the only relatively cheap ones I know about are the (discontinued) Chevy Volt, the base Tesla Model 3, and the Volvo EX30 that just came out (surprise! it’s Chinese).