Where are you getting those numbers from? Tesla's specs pages say 1777/1840kg and 1911/1981kg
for the standard/long-range Model 3 and Model Y respectively:
https://www.tesla.com/ownersmanual/model3/en_cn/GUID-5656213...
https://www.tesla.com/ownersmanual/modely/en_cn/GUID-E47C4A6...
The Model 3 is undoubtedly still a heavy car, but the bulk of that is the battery pack, so the weight will go down as battery tech improves. Maybe it already has compared to your source?