I would be shocked if tensorflow optimizations where useful 1:1 for stock Intel chips or GPU's. So, there is still plenty of lock-in even if your process runs. GPU vendors love to play this game by helping optimize games.
All of the comparable tools are practically locked into nVidia gpus/CUDA. TensorFlow is rapidly reaching performance parity on that hardware [1] and can now be run on this so it's actually sort of the least locked in framework.
It's possible, but I think that the majority of ML optimization as seen by a programmer using tensorflow is more about optimizing the balance of accuracy, training & inference speed, and memory use, and a lot of the solutions in this space are pretty hardware independent. There's an entire other type of optimization about, e.g., making conv2d insanely fast, but that's not something that a typical data scientist-type user deals with.
(To elaborate -- it's questions like "how deep should I make this convolution? Should I use tf.relu or tf.sigmoid? How many fully-connected layers should I put here, and how big should I make them?". These are really knotty deep learning design questions, but they're often h/w independent. Not always - we certainly have some ops on TF that we only support in CPUs and not on GPUs, for example - but often.)
1. Best price/performance is tensorflow right now. So, the best software choice is platform X.
2. Then in 2 years.. Well we are using Platform X so tensorflow is clearly the best option.
In other words once you pick conv2d, you tend to also stick with whatever conv2d is optimized for. Which also means HW vendors love to help optimize popular platforms.