We'll have national firms emulating Starship within 5-10 years.
Once SpaceX has got Starship working even only for LEO missions, China will have a clone up and running within two years. ULA might be a bit slower due to overly zealous bureaucracy.
Eventually these launch providers will mean SLS gets cancelled with NASA funding switching more to pure science (eg: building missions to look for life on icy moons, not the rockets to get them there).
Congress will continue to hamstring NASA even as their best and brightest depart for commercial operations with bigger R&D budgets.
As for the jet engines, is that what you know or what you have been told? What is the provenance of that data? Is there any chance that you are victim to a Chinese disinformation campaign?
And considering BO had previously said they'd have manned missions by 2018, I'm skeptical of anything in their forecast.
In USA there is obviously BlueOrigin (well, they have to get to orbit; will they in 5 years?), so no too much worries.
I'm not sure they have quite the history you're implying.
Here's the Carmack podcast where he talks about it. Fantastic listen for anyone honestly. Carmack is a fascinating guy.