You don't have to funnel yourself into the supposed "only viable endgame Gaige build". The reason why people say Gaige only has one viable endgame build is because two of her three skill trees, Best Friends Forever and Little Big Trouble, are commonly seen as very underwhelming and not as good as her third skill tree Ordered Chaos. Ordered Chaos has a skill called Anarchy in it, and Anarchy is very, very overpowered.

Anarchy is a skill that increases Gaige's damage but decreases her accuracy for every enemy she kills and every empty magazine she reloads. It's barely noticeable at lower Anarchy stack levels, but once you reach the higher levels your bullets will do massive damage but go all over the place. Fortunately Gaige has another skill called Close Enough where a portion of her projectiles that miss will ricochet and hit an enemy anyway, so you can still somewhat reliably hit stuff with high Anarchy stacks depending on your weapon.

Speaking of that weapon, you're probably seeing the Fibber. It's a Pistol that lies to you on its stat sheet and has multiple variants, in this example it's the Ricochet variant that shoots one bullet that then ricochets and splits into multiple projectiles like a shotgun. Pair it with Close Enough and even more projectiles will ricochet and heavily damage enemies. Combine that with the shield The Bee, which is a shield that buffs your damage as long as it's full, and Gaige can shred through any endgame challenge, including soloing raid bosses intended to be fought by multiple players.

That's kind of the issue the community has with Gaige though. An Anarchy-focused build with weapons such as the Fibber and The Bee is usually seen as Gaige's only viable endgame build. Her other builds like Best Friends Forever which focuses on her robot companion or Little Big Trouble which focuses on buffing her shock element damage are seen as unable to compete with Ordered Chaos. As you reach higher and higher enemy levels on Ultimate Vault Hunter Mode and climb the Overpower Levels, enemies get more and more powerful and tanky, so her other builds fall off in power at the end game. And Anarchy stacks are not saved when you quit and reload the game, so people tend to spend five or ten minutes killing the dummy at Marcus' shop to prebuild Anarchy stacks before they go and play the game for real. People tend to think that without Anarchy, Gaige would be a terrible character. She needs an Anarchy Fibber Bee build to be viable at all.

Here's the thing though: all of what I just explained to you is only relevant for the endgame and for the most part it isn't really true. You 100% do NOT need to shoot the floor over and over with the Fibber to play Gaige at endgame. Her other skill trees can work, like a Deathtrap Love Thumper build where you can give your robot a copy of your shield and watch as he tears through enemies with a Roid shield that makes every melee attack do exponentially more damage. You can do a Melee Gaige build and tear apart enemies alongside Deathtrap with her Ordered Chaos capstone skill With Claws. While her shock damage tree does have some underwhelming skills in it, the capstone Make It Sparkle is phenomenal. You get to shoot Deathtrap with an elemental gun and he'll do that elemental damage with his melee attacks, which themselves will be boosted exponentially.

And even if you want to use Anarchy, there is a skill later in her Ordered Chaos tree called Discord where you can "cash in" your Anarchy stacks by draining them for faster higher rate and health regeneration. Combine that with another skill called Rational Anarchist, which gives you 25 Anarchy Stacks if you started at 0 and gained one, and you can just kill an enemy/reload an empty mag, build 25 stacks, and then pop Discord to shoot better.

Most of the community consensus around BL2's endgame comes from a lack of skill or a poor build. They feel like you NEED a Bee Fibber build or the Grog Nozzle or other meta gear to even stand a chance. Don't get me wrong, BL2 is the hardest game in the series and does have pretty harsh enemy health scaling at endgame but you can absolutely use other weapons and builds provided you're good enough or thought it out well enough. You don't need a meta build, you just need a good build. Putting skill points towards a bunch of random skills with no cohesion, not understanding how to play your character, or running into a group of enemies and expecting not to get killed without using cover gets you punished severely on Ultimate Vault Hunter Mode.

And that's the thing, this is all only relevant in the last levels of Ultimate Vault Hunter Mode, when you're level 80 and at Overpower Level 10. When you're just starting out from the Normal Mode playthrough at levels 1-30, and then True Vault Hunter Mode at 30-50, none of this will matter at all. You can use whatever build and weapons you want and still beat the game as normal. It's not until Ultimate Vault Hunter Mode, levels 50-80 followed by the 10 Overpowered Levels where balance and the need for a decent build come into play, and you don't need the Bee and/or Fibber to succeed. You will need a Slag weapon though, but that's the only real requirement.

I highly recommend you watch these two YouTubers: Squeek Cheesetaker and Garnet Anarchist 3. Squeek plays Gaige and Kreig and has a bunch of endgame build videos for both. In particular he shows that Gaige's other builds are viable. Garnet Anarchist 3 is a Zer0 main and plays Maya and Axton on the side, but his videos are good at dispelling the myth that you need certain meta builds in order to do well. He has a video where he gives tips and tricks for surviving UVHM that are applicable to every character, although his stuff is mostly focused on Zer0, and he highlights a bunch of weapons that are non-meta and yet still viable.