Are dilated triangles basically just similar triangles?
In a dilation the image has a specific position relative to the original figure. This is not the case in similar triangles where the sides are in the same ratio but the position is not considered at all.
In a dilation (or enlargement), the position of the triangles is important as well as the size of each triangle.
The scale factor is an indication of how much bigger (or smaller) the image is than the figure and how much further or closer) it is from the centre.
Therefore while the triangles are similar, the image has an exact position relative to the figure. Not all similar triangles represent a dilation.