The Model 3 motor works on a fundamentally different principle to the ones in all Tesla's previous cars, but it's very similar to the motor technology used by all the other modern electric cars. The best analogy I can come up with is that it's like a company which has only produced diesel cars claiming their engine experience gives them an advantage over all the other car manufacturers who've been producing petrol cars for a while when announcing their first petrol car. (It's not a perfect analogy - a car manufacturer which did that could probably reuse a lot more of their existing engine tech and experience than Tesla could.)
More specifically, Tesla's big advantage was that they had very sophisticated drive technology for using AC induction motors in electric vehicles. That's even where their name came from - this kind of motor was invented by Nikola Tesla originally. No-one else had this tech. With the Model 3, they abandoned this in favour of permanent magnet brushless motors very much like the ones all the other manufacturers were already using. Because of the very different way in which those motors work, they require completely different drive algorithms, pose entirely new engineering and materials challenges to manufacture, and give very different perforrmance characteristics. Tesla basically took all of the motor work that was supposed to give them a headstart, abandoned it, and started almost from scratch where the other manufacturers were years ago.
More specifically, Tesla's big advantage was that they had very sophisticated drive technology for using AC induction motors in electric vehicles. That's even where their name came from - this kind of motor was invented by Nikola Tesla originally. No-one else had this tech. With the Model 3, they abandoned this in favour of permanent magnet brushless motors very much like the ones all the other manufacturers were already using. Because of the very different way in which those motors work, they require completely different drive algorithms, pose entirely new engineering and materials challenges to manufacture, and give very different perforrmance characteristics. Tesla basically took all of the motor work that was supposed to give them a headstart, abandoned it, and started almost from scratch where the other manufacturers were years ago.