So looking at the Premium Sedan market share in the US (which is arguably the most important market in the world) the numbers show a 1% decline in sales for 2020 - "The midsized car segment continues to lose share in the US car market in 2020. Sales were down 22% in an overall market down 14%. As a result the share of midsized cars drops by 1 percentage point to 10.2%, and in absolute numbers, the 1.5 million sales make this the lowest year of this millennium and long before it." - from https://carsalesbase.com/us-car-sales-analysis-2020-midsized...
So while the premium sedan category (including Tesla 3) is declining overall, Tesla is reporting to its shareholders the "great achievement" of winning that sales declining race.