yeah but i want it to be default.
There's no option to make it "default". But the ⇧⌥⌘V works "first time, every time", that's what you have to use.
There are other, more expensive options. I use TextExpander for many things, but one of the snippets I have is to use a simple keystroke (I use ;cb to trigger it) to paste unformatted text from the clipboard. TextExpander is about $35, so there's a cost involved. For this single use, it's way
too expensive, but it gives me way more than $35 worth of utility.
My point is simple... use what options are available to you - at whatever cost (in terms of dollars and/or convenience) to get what you want.
The ⇧⌥⌘V is "free" in terms of dollars, but will require you to remember and apply is when you need it.