Just a minor correction: USA != World. But yes, the pick-up market in the US is huge. Success will depend on 1, how crazy Elon got with the design (one key Tesla success factor was that their cars look like normal cars) 2, how quickly thy can start making them.
PS: For instance the US and European new car market is roughly the same size (2018 US was 17.3M Europe was 15.6M), but about 8 of the European Top 10 would fit in the back of an F150.
But those top 10 sellers also deliver exceptionally cheap running costs. As I understand it, Europe has very high gas prices. So with an EV having a much lower running cost, we may not be able to extrapolate the European preference for highly fuel efficient gas cars to EVs.