。
The point is, mothers are too busy.
Literal
The-point [topic-は] mothers [subject-が] busy-too-much [that-という-こと] is.
要は ('the point is / in short') is a summarizing connective. ~ということだ ('the meaning is that / what this amounts to is') frames the whole sentence as a summary. ~過ぎる is the intensity suffix 'too much / excessively.'