Only some others? Maybe in 2018-2019, but not by 2020.
100-150 pure BEV models will be available around the world by 2022-2025 (not all of them in all regions, hence the wide range).
Second, the Model3 is not the first mass-produced EV, that was/is the Nissan LEAF - (still) made in three plants around the world:
Production will pick up further once the LEAF with a larger (likely ~60kWh) battery version becomes available.
The internatiobal Model3 rollout is so slow that the upcoming LEAF could even be available first in some markets.
The VW ID (or what its final name wil be) will also be mass-produced by the end of 2019:
Volkswagen ID hatchback: first prototypes to be built next month | Autocar
That’s the start date (late 2019, early 2020) for most large car makers.
Virtually all mass-market cars coming after 2020 will be built based on dedicated EV platforms with mass-production in mind - these are not one-offs or small runs to comply with regulations any longer.
Anyone with a buy and hold position in Tesla ignoring this massive competition (not just long-range EVs, also high-speed charging networks at 150-350 kW) will be in for a rude awakening.
The coming seven to ten years will be great for EV buyers, but bad for most EV investors (margin squeeze even as revenues multiply, shark tank in mass-market segment...).
We have seen this scenario play out in solar panels from 2008-2015* and we will see it play out in EVs from 2018-2025.
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* Sector pioneer Solarworld just went bankrupt for a second time in 2018.