You’re not wrong factually, but it doesn’t mean what you’re suggesting it means. Their share went up because EVs aren’t selling as much anymore. All companies including Tesla are selling fewer EVs. They just have a bigger share of the smaller pie, which isn’t exactly a success when you only sell EVs, but your competitors also sell non EVs.
Edit: Constant is the wrong word. Resilient or consistent is what I was trying to say.
Competitors leaving the market means less competition which is a good thing for Tesla. If the market for EVs returns in the future (if, say, the next administration reimplements the incentives), Tesla will be there to reap the benefits.
Their sales did not remain constant.