Probably something to do with being rich AF.

Also, it’s easy to say he should’ve packed it in, but it’s gotta be hard to walk away from a band like that.

He just lost that 'magic' spark in his writing. Most artists output in their 30's doesn't compare to what they did in their 20's.
In my opinion, his biggest mistake was letting Andy and Gem write for the band, it really watered down the three albums we got with them on board.
I didn't see the point in letting them write, except for giving them some royalties. Their songs are just sub-par Oasis by numbers. Noel had the songs, the B-sides from HC and a lot of his NGHFB can be dated back to DBTT and DOYS.

Noel stopped writing all the songs on the album, not as inspired as the 90s and they failed to progress and experiment as a band, simples.

What was so good about the HC b-sides? I'm yet to be convinced that Noel really had the songs at the time, and if he did it was his call to put them on there.

Nah.

Just Getting Older - great
Idlers Dream - great
Shout It Out Loud - dull
You've Got The Heart Of A Star - extremely dull

I think they're all pretty dull although I do have a soft spot for Shout It Out Loud. I just think it was an uninspired time for Noel in general. I think asking Gem and Andy to contribute was at least in some way bourne of necessity.

Someone, maybe Elvis Costello, once said that you have your whole life to write your first album but you only have a few months to write your second (this is definitely a paraphrase so forgive me for getting it wrong). In Noel's case, he had more than two albums worth of material before making Definitely Maybe. After that, he didn't have nearly the same amount of time to devote to songwriting. And as others have mentioned, the output in those first two years was extraordinary, particularly with 3 songs on each single.

But coupled with that, I think that the pressure got to him in ways that gets under-discussed. For some great artists, a huge hit can be both a blessing and a curse. It can be a curse because once you achieve it, you either know you won't be able to top it or you become paralyzed trying to top it. An artist I love is Brian Wilson and in late 1966, he was working on an album called Smile which was shaping up to be his greatest artistic achievement. Then, after months of excellent work, in December of 1966, the project became rudderless and entirely unfocused. Many put this down to both Wilson's own psychological troubles as well as his drug intake, and both are surely part of the problem. But also part of the problem was that in November of 1966, The Beach Boys scored the biggest hit of their career, Good Vibrations and Brian realized that while he was making amazing music he didn't have a single to follow that from Smile. The next four months was spent making and re-making and re-re-making Heroes and Villains, which was meant to be the follow up single. Finally, he pulled the plug on the project entirely and never became as active in the studio again.

I do think that despite all the bravado that the unpredictable success of Morning Glory really threw Noel for a loop and being the person he was, he genuinely wanted to top it, convinced himself for a short while that he was doing it with Be Here Now, realized he hadn't, maybe realized he was never going to, and then quite simply pulled back a bit.

Also, I think to some degree his ego was a bit shattered (however much Noel Gallagher's ego can be shattered) after Be Here Now. Remember this was a guy who for three years had been all over the press as the self-appointed arbiter of what constituted good music and what constituted shit music. He saw himself as THE authority in that regard and, to be honest, for a few years, who could blame him? If someone releases Supersonic, Live Forever, Cigarettes and Alcohol, Whatever, Some Might Say, Acquiesce, Wonderwall, The Masterplan, Don't Look Back in Anger, Morning Glory and Champagne Sueprnova in less than two years, they would appear to have pretty good knowledge of what is and isn't good music.

But after Be Here Now (an album I happen to like), I think it became a bit difficult for Noel to show his face after that, given what had been his self-appointed status on Knower of all things Music. I think he questioned his own instincts from that point forward, no longer sure if what he had was a good song or a bad song. He would tell the press it was brilliant but then a few weeks after release would say something to the effect of, "I could tell when we were mixing it that someone wasn't quite right." I think from about 1998 on, Noel didn't have the confidence in his own ability to pick a sonic direction for the band and run with it and so the band, really, was kind of directionless.

So I think there were a few factors at work.

It’s hardly like Oasis went to pot.

Beside the dull HC, the other albums are solid in their own right. And each album cycle still produced the utmost classics that would have been held in high regard in the 90s.

The problem was that Noel turned to band diplomacy for song writing when he was going through the motions of both SOTSOG and especially HC. When he rediscovered his songwriting prowess, it would have been too damaging to revoke LAG’s (wow that’s an acyronmn we haven’t used in years!) opportunity to write songs, especially brother Liam’s.

Noel not taking back full control from 2005 onwards was the real issue. The band diplomacy had its place, but we didn’t need shit like TNOR and ABWR when Noel was back to writing classics like Lyla, TIOBI, POTQ, TSOTL, FD, TT, etc....

DBTT and DOYS we awful albums. Noel should have went solo a lot sooner

No.

Yes! Lol liam sounds gross not that I think he's sounds to much better nowadays. Liam was holding Noel back