Moving / resizing text boxes increases file size

- Always "Save As", instead of "Save", when your document is finished to reduce its size.

- Untick this option that increase multipage PDF forms size:

- Unless there is a constraint or good reason, you should limit yourself to using the 14 PDF standard fonts, those found at the top of the font list before the separator line (Courier, Helvetica, Times, Symbol).

See: https://appligent.com/what-are-the-base-14-fonts/

Using another font causes it to be fully embedded in the PDF, which increases its weight accordingly.