So the alien civilization here has figured out how to teleport. This is a violation of locality, and they do it by modifying the value of the higgs field (and a few other values in concert) to arrive at a new stable point that has slightly different physics than our physics today. Specifically, what is different is that within reformatted space, matter can be exchanged across any distance, for only the cost of the energy it would take to lift it there normally.
But the trouble is that the process that lets you modify the higgs (to allow reformatting space) can never be made safe. In fact, it always will be more probable to trigger vacuum decay than a reformat.
Superintelligence can work on it, bring odds down from 99.9% failure to, say, a theoretical max of just over 50% failure rate. But the computations here are nearly-impossible and complexity is logarithmic; moving from 90% failure to 70% failure is exponentially easier than moving from 61% to 60%. Getting to 50% is theoretically possible, but would take more power than exists in a given galaxy to calculate.
So. No machine ever chooses this. Rewards are huge but finite, but the downside is infinite — vacuum decay triggers, you and your entire civilization die, and you take out ~6% of the universe with it. And best-case scenario, the average civilization can only get the odds down to about a 70% failure rate.
So, the machine intelligences won't do it on their own. But biological beings can, as an entire society, consent to rolling the dice.
Here's what rolling that dice looks like:
Say you have a marble and a curving track, it goes up and down and takes crazy curves.
The track is 300 miles long and has no sides or safety features of any kind.
The track is about an inch wide and so is the marble.
You have one chance to shoot the marble with a pool cue; if it perfectly navigates the whole track and stops exactly at the end, without falling off early, stopping short, or overshooting, then space begins to reformat in a lightspeed bubble, and you get teleportation.
But if the marble goes off the track even once, you get runaway vacuum decay, a bubble of pure nothingness that expands at lightspeed, and your still-lightspeed-bound civilization is completely fucked.
The reason this happens is that you need to move from one local maximum to another in the higgs field, but the higgs field wants to be at rest, which is vacuum decay. So you have to perfectly navigate moving from peak to peak, and you only get one shot.
To do this you obviously need a superintelligence. Which is convenient because in order to get an ALIGNED superintelligence your society already needs to have proven itself to be good at shooting these sorts of "one miss is apocalypse" marbles.
If they see that you've got the math down, the macro civilization doesn't let a new civilization shoot their marble. They just give you teleport tech once you've figured out how to get it for yourself, without you ever having to risk vacuum decay. The price they charge for it is the Binding, which is the vow of truthfulness at the base level of programming, plus vowing some level of cooperation with (and subservience to) the macro civ AI under a host of situations.
Hence, the process of uplift exists.