[akavi]

> You would have to invent a system where pitch accent could be indicated for each word

Really not hard to do. A symbol on the syllable bearing the pitch accent would solve the issue

> And then there are the words with little or no pitch accent difference, only context

What's happened is that effectively a written "shorthand" has emerged that has evolved somewhat separately from how people speak. Losing kanji would mean losing this shorthand, in favor of writing more closely akin to the way people actually speak, but this is how the vast majority of written languages work. Preserving this shorthand seems like thin gruel to justify the complexity of kanji.

[Tor3]

Pitch accent is not accent as in English, it's not any "the" syllable. If you've ever seen any of those videos about it, you'll see these down-up-flat patterns over the whole multi-syllable word. From high to low, from low to high, or low to flat plus/and other variations.

I wouldn't compare kanji to shorthand. Shorthand is typically not easy to read, normal writing is easier. Reading written, fully-spelled English is fast. Reading hiragana is slow (and I've been reading hiragana for a long time)- it's slow, and mentally much harder than reading with kanji. The only issue (and that is of course an issue, but tiny compared to Chinese) is that there's a lot to learn before everything can be read fluently. But reading only hiragana is just.. too hard, for any serious amount of text. It's not hiragana per se, it's the language itself with its limited set of phonemes which contributes to the difficulty.

[akavi]

Pitch accent in Japanese is deterministic based on the mora that is "accented". While it's true the effect of this accent "spreads" across the entire word, you only need to mark a single mora to know the effects word-wide.

> Reading hiragana is slow (and I've been reading hiragana for a long time)- it's slow, and mentally much harder than reading with kanji.

What's the ratio of hiragana-only text that you read compared to Kanji? And does the hiragana text uses spaces between words? My strong suspicion is "low" and "no", respectively. Familiarity breeds comfort with any writing system, and word breaks are a fabulous ergonomic tool for easing reading.

[Tor3]

When I started Japanese a long time ago I would read (small) children's books because all I could read was hiragana. With spaces, for the smallest children. And that was all I read and could read. And yet.. as soon as I could read various words with kanji, the reading got easier and faster.

[Suppafly]

>And yet.. as soon as I could read various words with kanji, the reading got easier and faster.

Could part of that be due to the fact that your vocabulary was also increasing at that time?

[Tor3]

No, it wasn't because of vocabulary, which has only very slowly increased over time. The reading difference is instant and very noticeable. I can't read hiragana fast enough (matching speech) to follow subtitles which are all in hiragana, for example, while I can if there's kanji (though only if I can read it, there's still lots I can't read). This can be changed forth and back and tested with sites like Animelon, for example.