By who??...someone who left the Catholic Church and decided to do it their own way??
That statement is flawed in more ways than one.
It is not a matter of bb having decided to do it "her way" as if she did that all her own. She certainly has not abandoned the Holy Writ concerning Christ, so is no freestyling free-booter.
To somehow imply that she is (which is they way your arguments nearly without fail come across) is just so much cheap insult, convincing no one of anything other than being further continuing evidence of your own bigotries.
Many of the claims which Romanists are fond of making, have been falsified --- not necessarily by individuals per se, but by objective facts which are independent of mere opinion.
If you truly do desire to "convince" others that they are in error ---try addressing precise items of conversation as those arise --- instead of repeating the same stale bigoted opinion & argumentative thrown out as some sort of magic blanket cure-all that will fix everything, as if those viewpoints and opinions refute all aspect & item of dissent no matter what (regardless of what the more actual & objective facts of the matters truly are).
Is that too much to ask?