you better watch the movies again because the T-Rex absolutely ran. In real life they were able to run too. You need to do more research bud.
No, you need to watch the movies again... among the various "running" scenes, including the infamous chase scene in the original movie, the T-Rex is clearly moving with one foot always firmly placed on the ground, similar to how it's shown to run in JPOG... in technical terms, that's still walking, no matter how fast you're going, and is considered far more accurate for an animal the size of a T-Rex than the awkward jogging animation they gave it in JWE.