Haha, can see that this can be a "war" between sight-reading and play-by-ear. But I think we can discuss with educational benefits.

One simple example that sight-reading will survive is because composers want their works to be reproduced correctly.

Maybe a piece played by a single instrument can be reproduced by a person with great ears, but a film music typically comprising many instruments would be better reproduced with scores.

I've always looked at scores with thick chords, maybe both hands playing about 8 notes together, and wonder how someone can pick these 8 individual notes out easily by ear. It's quite obvious which side I'm on.

Not really a "war" but more a "divide". In fact I was invited to delivery a talk on this topic at one of Pianovers's special meetup at the Bliss House some months ago. In the talk I mentioned each serves a different set of purposes, and the merits and shortcomings of each. If you are keen I can email you the slides.

Another vital insight to share with regard to play-by-ear is as follows. If we treat classical/art music as THE genre, then of course sight-reading carries heavy weight. Don't get me wrong, I'm a classical music specialist (among all genres) and I advocate all music learners go through at least the main classical repertoire.

However, the world of music is more than the classical genre. We have several other genres of music whereby "scores aren't available" for such pieces because of the nature/context of things. For example, traditional folk music of several countries/regions such as Greensleeves (England) and Sakura (Japan) - we can't really traced their original composer. And even if we are able to, most of them did not pen their works via the 5-lined stave. Many could be played/sung throughout the generations/eras. And if we need to rely on scores to play such pieces, we can only find specific score versions done by specific ARRANGERS. So we are playing someone's arrangement, instead of its original version (which has no score). Play-by-ear and improvising/arrangement skills of us (as pianists) are thus coming in handy for such purposes.

Even in the mege-genre of pop music, and also other genres like New Age music and Soundtrack music, many composers don't create the stave notations - they only produce the final product (the audio track). As such, music score transcribers start to earn some market share by notating these to various degrees (which again is subject to their own "arrangement"). So in this context, wouldn't it be better that we play by ear?

Black cat or white car, as long as it can catch the mouse, it's a good cat.

Using this philosophy, it doesn't matter the method to learn, as in the end, you achieve your aim. Of course, your aim might be different from me.