The break up after Knebworth thing seems to be one of them Noelisms that stick as an opinion amongst fans sometimes. It's pretty apparent watching any Oasis interview from 96/97 that he wanted to take them that step further and there is no way they'd have stopped.

Noel wasn't anywhere near a good enough singer or performer to go solo either. He knew he had the best frontman in the world and a much better chance of success with the current formula. Why risk all that to go it alone?

Noel wasn't 20 or 21 either, he was already 30ish by the time of Knebworth. Imagine his thoughts about leaving it a few years and potentially looking older and being a forgotten relic of a bygone era. He wanted to strike while the iron is hot. There is absolutely nothing to suggest leaving it say 5 years and made a comeback would have amounted to any more success. In fact the songs could potentially have been way worse if he was just sat around counting his money on holiday. People live in this fantasy world that he'd have undoubtedly written the combination of Be Here Now, Go Let It Out, Fuckin In The Bushes, Gas Panic and the singles off Heatehn Chemistry and we'd have the ultimate oasis comeback album. 

It's all easy to say in hindsight but imagine if Be Here Now was just as good as Morning Glory. No one would be questioning anything. The question is more what could have been done to make Be Here Now a success and we've all debated that a million times.