Growing and developing Earth (Expansion) in global tectonics?

That theory exists because someone made it up. There is no evidence.

The Earth is a rock, coasting around the Sun. How could it "grow"?

Plate tectonics is real, a growing Earth is fantasy.

Expanding earth was the original concept produced to explain the movement of continents, the idea being that, as the earth expanded, the continents would split and move further apart. It is not generally accepted for a number of reasons, the first of which (as has already been mentioned) is the mechanism of growth. Growth would require either new matter forming at the centre of the earth or a reduction in the density of the planet, neither of which have a plausible mechanism or observational evidence to back them up.

The second problem is its explanation of features. Pure expansion can not, by definition, create collisional features which means that every mountain range, thrust fault and fault reactivated in compression is inconsistent with the hypothesis. An explanation could be periods of expansion and contraction but that would require a trigger for each stage and still can't explain the observed ongoing nature of subduction.

The third, and final issue comes back to observation. Not only is there no direct observational evidence that links uniquely to expansion, there are direct observations both from GPS and VLBI that the earth is not expanding.

So, to put it simply, the expanding earth hypothesis is an outdated idea that is not alone in providing a mechanism for continental drift and is at odds with the majority of the observations we have. Plate tectonics provides a much better explanation, which is why it superseded expanding earth around the 1970s.

The cause of expansion is the major reason why this theory does not recieve widespread acceptance. Ironically, plate tectonics suffers a similar problem of mechanism especially since 3D seismic tomography failed to find evidence for the needed mantle convection.

Incorrect. This is not part of modern geology (indeed, it requires overlooking the bulk of the geologic record), nor is it a theory in the sense of Plate Tectonics.

It's a fringe hypothesis, and a long discredited one.

The theory isn't valid, it is not accepted by geologists anywhere.

The Earth is not expanding or growing.