Having said that... this is mostly a slogan and makes for good Youtube videos, but it falls apart the moment you subject it to even the most basic scrutiny. For one... it doesn't make sense to talk about a speed through time since speed is literally a measure of change with respect to time, so a change in time with respect to time doesn't make any sense.
But as a slogan, it captures the idea that motion through space and the rate of your own clock are tightly linked together.
Only if you're talking about other people's clocks and not your own. Your own clock is one second per second, but someone else's may be slower or faster relative.
So then you say take someone else's clock and compare it to your own clock, but that is still just a pure number. A speed is not a number, it has units like meters per second. A ratio of two clocks has no units at all, the units cancel. Whatever number you get, 3 or 9, it's just a factor by which two clocks disagree. You can absolutely interpret this ratio as a rate, but that doesn't make it a speed.
And a speed is exactly what the slogan needs, because the diagram/geometry it's using involves a right angled triangle where on one side of the triangle is your speed through space, and on the other side of the triangle is your speed through time, and the hypotenuse of the triangle is fixed at c (since every object travels through spacetime at this fixed speed).
For that to mean anything both sides have to be the same kind of quantity. You can't put meters per second on one side and a bare number on the other and call it a triangle. Nor can you patch it by multiplying the ratio by c to give it units, because the thing you get then grows as you speed up instead of shrinking. Either it has the right units and the wrong behavior, or the right behavior and no units at all. There's no version of this geometry that produces a consistent picture.
You can say the age of the universe is 14 billion years, but that's in our reference frame.
In another reference frame it may be a different number.
People working at AI labs like yourself should figure out how to stop destroying science so there are still people who know enough to call you out when you spread misconceptions.
> preferred
While these are meaningful conventions, they are being measured with respect to that rest frame.
The local group moves at some few hundred km/s velocity relative to the CMB, so the age of the universe in our reference frame will be slightly shorter than that preferred frame. Call it ~10^-7 shorter but still ever so slightly shorter. That was my point.