Why not a generic accordion menu that picks up theme style?

Hello.
https://www.ads-software.com/support/plugin/bellows-accordion-menu/
The need for an accordion menu is obvious.
What I don’t understand is why it hasn’t been designed to just pick up the existing menu style in my wordpress theme. I don’t want to start over, I don’t want to redesign, I don’t want to spend hours and days tinkering with editing the look. I want exactly the look I have now, but as an accordion.