Tesla and SpaceX success is depending on the public opinion of Musk. If he ends up paying 15 billion (or whatever the number is) over a botched take over, one that had a negative impact on Tesla shares, this opinion might just change. In which case Teslas future preception as a tech company might be at risk.
An advantage that we cannot be sure exists to begin with since SpaceX isn't piblishing financials. And for some launches Arianne Space is already now competitive using the Arianne 5, by all means an out dated design, one that was initially intended to carry a European space shuttle into space.
More generally so, I have no idea why people expect any company to own a market completely. Any market is usually big enough for one than one company to be successful.
SpaceX's product isn't reusable launches it's just launches, the reusability is their competitive advantage. There's a lot of other launch providers out there.
It probably depends on how much you need to think about it. If you have a minion to whom you can say "I'd like to buy Twitter, go figure it out, then let me know where to sign", there's a lot of room for being impulsive.
