A well made extract beer can be better than a poorly made all grain beer, it's that simple. That's why extract beers can win blind contests against all grain beers too. It's not the method use that determines if a beer is good or lousy, it's the brewer, and the care and attention they place on their process.
I know, over the decade, I've tasted at club meetings and brewing events crappy all grain beers where the brewer thought his crap didn't stink because he owned a blinged out all grain system, but didn't pay attention to basic things like temp control, or pitching enough yeast or rushing the beer, or not letting it bottle condition or doing a crappy job of sanitization.... and I have tasted really excellent first efforts by extract brewers who long before they brewed their first kit, stumbled on to places like this, read all they could and applied those basic level care to their beer- They, did a full boil and/or did late extract additions, made a yeast starter with liquid yeast, they rigged up a swamp cooler to maintain their temps during fermentation, the bought starsan and threw out the packet of saniclean, they tossed their kit instruction that said the beer would be ready in a week, and took gravity readings before racking or opted to try a month long primary to let the yeast clean up after themselves, they let their beers bottle condition 3 or 4 weeks... and there beer was lightyears ahead of the AG brewer who thought he knew everything and did nothing...
There's a lot of egos that will tell you 1 method is better than another, or extract is better than AG, but I made some damn fine beers the first couple years of extract brewing, of course I rapidly stopped brewing with kits in favor of building my own Extract with Grain recipes or brewing with recipes from here that were highly regarded, or in BYO magazine.
If you are using FRESH extract, from a high traffic supplier, like online or a busy store... you're using good quality ingredients. People think for some strange reason that extract is "different" from all grain people do.. but when we brew all grain,
we're making extract the only difference is that the maltser is blending grains like we do, and then boiling the hell out of it to concentrate into an easily packaged concentrated for for sale, or going further to evaporate the water out and poweder it, but contrary to what a lot of people, even all grain brewers seem to think, EXTRACT is not something artificial concoction- it's no different chemically than what I make in my cooler, just thicker.
The bias against extract stems to what I believe is self-delusion... people blame extract for the reason their first brews sucked rather than admitting the simple fact that they sucked initially as a brewer... that they were IGNORANT of things- like those things I mentioned above, AND we generally also listened to those crappy instructions that told us our beer would be fully fermented and bottle conditioned in a week.
And then, before they even learn to make a solid extract kit, they jump to all grain, and maybe apply some of the tips they read on here and make decent beer... then they rail against the "evils" of extract.
I've said it for years, and few will try... I have suggest to those AG snobs, that they go back one day and actually re-brew one of their first hated extract recipes/kits,
but applying everything they've learned in their years as an ag brewer and see if just maybe they can crank out a decent tasting beer, a lot better perhaps than they recall.
I tell people, if you make great extract beers, are happy with them, and don't feel the need or have the desire to challenge yourself, to "up your game" then keep doing what makes you happy. Some people do extract for decades...they may be in the hobby simply because it's cheaper this way, or don't have the time or incentive to get more complicated that what they're currently doing.
If you've done kits and make decent extract beer, but don't want to go all grain, consider making your own extract recipes..that's pretty challenging. That was my next step from kits... And if you look at a couple of my extract recipes on here, I made some good one.
But if you want more challenge, or want more control, then go to the next level... for me it was a progression from my own extract with grains recipes... there is a limited amount of "base" extract easily available... or was 10 years ago.. if I for example wanted an all marris otter base malt (or an all pilsner "SMASH") I was sort out of luck. Plus with AG brewing you get to control a lot more variables, mash temp, the chemistry of the water used (with extract you are basically "stuck" with the water profile the maltser used to make said extract.,) so it's really difficult to re-create a Burton On Trent English Ale water is pretty important.
But again it's not one is better than the other.... it's an ingredient like anything else... and just like cooking, even the humblest ingredient (think offal) in the hands of a master chef can be a thing of beauty, a $50.00 piece of aged Waygu Tenderloin can be turned into **** by an uncaring or egomaniac arrogant chef. Same with extract... hell same with a much maligned mr beer kit...
Learn to make the best beer you can
with any ingredient or with any method you choose to employ, regardless of what someone else might think.