SpaceX will have a decades of commercial launch dominance

In 2018, Spacex could fully master reusable rockets that require no refurbishment for relaunch. Spacex is already the low cost launch leader. Fully reusable generation one capability will already reduce costs in half even while maintaining margins. No future launch capability is a threat to Spacex dominance of commercial space launch.
Blue Origin is working on reusability but they are still suborbital. Blue Origin is targeting about 2020 for having an low earth orbit capable reusable rocket. They would still have to scale up production even after proving this capability. Spacex will have absorbed and consolidated a dominant market share.
ULA, Arianespace, China and Russia all have nothing remotely close to achieving the low cost and launch capabilities that Spacex will have.
China, Russia and Arianespace will have non-commercial payloads aka Military and Spy satellites that will be given to a national launch provider. Currently non-commercial payloads dominate the space industry. However, Spacex’s low cost and high number of reusable launch capacity will grow the commercial market.
Spacex will have about 20 launches this year and is targeting 40-50 launches in 2018 (going to one per week). Fully reusable rockets with no refurbishment and one day turnaround could hit 100-800 launches per year in 2019-2020.
Even at 100-200 launches at $15-20 million per launch in 2019-2020, Spacex would have about 90+% of the commercial launch industry.
There will be some innovative small payload players like Rocket Labs and Cubecab. IF Rocketlabs was successful and launched hundreds of tiny payloads, then combining them with ULA (for more funding) and making larger 3D printed rockets could be a path to a plausible Spacex competitor. Especially since the US military would want to have an alternative launch provider.
Spacex will prove out a massive lead in capabilities over the next three years
The Spacex Falcon 9 Block 5 should have 24 hour turnaround, require no refurbishment before relaunch and be able to relaunch a dozen times. The Falcon 9 block 5 should be launching by the end of 2017.
Spacex will launch the Falcon Heavy and will have the largest payload launch capability. Spacex will dominate launch from 5 tons to 70 tons.
Spacex will be introducing a new more powerful Raptor engine. They will initially use it for the upper stage of their existing rockets to launch more payload. They can use it to increase the efficiency and launch capacity for new Raptor version of their Falcon rockets.
By the end of 2020, IF Blue Origin launches their first reusable orbital rocket, Spacex will have launched hundreds of times and with 90+% of the market and with price and capacity leadership.
New rocket development programs from Russia, China, Arianspace or ULA would be years away. The programs would need to be technically successful and would need to find some way to leapfrog the continued rapid improvement of Spacex capability.
Spacex will have dominant technology, dominant market share and cost leadership and the fastest improvement of capability.
Spacex will incorporate 3D printing of parts and any electrical pump innovations. Spacex is and will be leading with batteries and materials innovation.
Spacex will be driving leadership in space applications with the launch of thousands of satellites for global high speed internet provision. The internet satellite network would provide $30+ billion per year in revenue.