Hmmm. I think I might disagree with this.

If you just lop off the introductory 'I think' when voicing an opinion - or sometimes even a fact - that will often make your contribution to the discussion seem arrogant and overbearing.

It indicates 'and no other view is valid' and/or 'you should know this already'.

That is likely to be off-putting to many, and discourage less forthright members of the group from volunteering their perspective.

The phrase is not nearly as redundant as some might believe. I think.