I don't think English and Japanese are directly comparable in this way, honestly. English spelling today is if anything most comparable to Japanese furigana pre-1946. — Yeah, believe it or not, even the phonetic guides meant to help people figure out the readings of the characters in Japanese had some maaaad historical spelling before, brought about by a lot of the very same types of sound changes that caused many of the confusing spellings in modern English.

For instance, take the word 東方とうほう touhou — the historical furigana was 東方とうはう touhau, and the reason why you read the "hau" as "hou" was in fact the same reason why you say the "au" in autumn with the same vowel as in thought, rather than with the vowel in Bauhaus. Likewise 菓子かし kashi had the historical furigana 菓くわ子し kuwashi, and that "uw" was silent for basically the same reason as the W in sword and answer.

Japanese was able to modernize furigana/hiragana/katakana to match the modern-day pronunciation precisely because it had those thousands of logograms to "fall back on", although the historical kana orthography lives on in the handful of irregular spellings still in Japanese — namely はha へhe をwo as particles are read as "wa" "e" and "o". The iroha ordering of the kana is also based on historical kana orthography,いろはにほへとちりぬるをわかよたれそつねならむうゐのおくやまけふこえてあさきゆめみしゑひもせす（ん） as it is a pangram in Early Middle Japanese; and Japanese will also sometimes employ historical kana orthography for stylistic purposes in a somewhat similar way to "ye olde shoppe" type spelling in English.

But anyways, yeah, I think that simply glossing English words with IPA ends up creating an image that English spelling is a lot more arbitrary and random than it actually is. So I would rather support some sort of method for clarifying English pronunciations that focuses on things like etymology in order to actually explain the relationship between the letters and the sounds. This ends up being more dialect-neutral, too.