Google isn't in it for just the money. They want to control our thinking as well, and given the kind of censorship that is happening on YouTube, if it is operating at a loss, they may not mind because it has other less tangible benefits.

For profit public corporations do everything for the money. There is no ulterior motive.

Gas stations make hardly any profit on gasoline. The margins on snacks, on the other hand...

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.