Youtube or other platforms may not make strong profits themselves, but contribute strategically or operationally to the overall Alphabet bottom line.

So the discussion here is not 'Is Youtube making a profit' but 'Does Youtube contribute, directly or indirectly, to the overall Google/Alphabet enterprise strategy?'. In that case, it is entirely possible for major acquisitions to not appear to be 'for the money' but are still essential in driving shareholder value.