I don't think anyone claims that conservative and reform judaism is the same as orthodox judaism, but as you also write, there is no reason to assume that these two movements will fade away.

which part of your claim does my remark on (c) support? please explain.

as for "the judasim we know and remember" - orthodox judasim itself isn't the same as judaism in "bait sheni" period etc., so I believe that for people in the 18th century orthodox judaism differed from the judaism they "knew and remembered".