At some point I noticed some of the cringey voicelines such as "All Unitis be advised: feminism is awesome"
said by oscar mike, the literal call of duty dudebro character after dominating a female char (can't remember if it was any or one specific). with that context, why is it cringy? also no idea why you noticed it only after a while, the whole writing was like that right from the start (which for me got more tolerable over time, to my surprise. toby tested it tho). what I never could shake was montana sounding like joe swanson from family guy.
The PvE was horrible and lazy, which became more glaringly obvious with the DLC which were just boring missions with the gimmick of replayability being different dialogue and lazy recolours for skins. It was Borderlands 2 with the voice-over with plenty of moments where you had to wait for the fucking dialogue to finish before the game would continue.
pve was fine, personally I would have loved for it to be a bit more random and dynamic so you don't memorize the exact spawns after a while and to make up for the limited amount of maps. least they gave characters different interactions and comments depending on team comp and character (like having a jennerit char go into some background details on jennerit maps or characters with their nemesis as boss etc.)
same for the dlc which had 10 different "stories" for the 10 playthroughs you'd do, some of them actually being damn great. the only stopgap I remember was on the experiment because spawns were all over the place, but since it was always the same you learn how to speed it up pretty fast.
still got more and better content in 6 months than overwatch got in the whole year (even considering the season pass which they could've just half-assed but didn't).
I sunk a disgusting amount of hours into the game, but the death knell for me ultimately was the fact that this MOBA-like usually went WEEKS without balance patches.

However it did direct my attention to Gearbox being run by exceptional individuals such as Pitchford and staffed by likewise morons such as Anthony Burch.
I only remember weird balance spikes with orendi being OP for quite a while and el dragon a bit too strong in the right hands (which was kinda offset by not being the easiest character to play) and then getting nerfed into almost uselessness for months. worst case you could still ban a pick.
for me the bigger issue was the almost zero communication (with their board software being some weird web 2.0 abomination, holy shit) and the community being retarded when it came to criticism or suggestions. like pointing out having a mandatory 5 minute intro movie you can't skip, then having a forced tutorial with an advanced character
you have to unlock isn't the smartest idea, it drove people up the wall. another thing was that gearbox never adjusted the game when it was clear pretty soon that the population would stay low. 5+ different queues with no backfilling is fucking retarded when matches can take almost 30 minutes. you also couldn't rejoin when dropped, so your team was extra fucked.
you couldn't even progress your character in custom matches since progression is disabled there (meaning you're SOL doing your challenges for your BIS trinket) and it took over 6 months to put in bot matches - where some challenges were buggy for another 2 months. suggesting custom matches having progression because cheesing the challenge grind isn't the end of the world was met with another blow up by some people (which I then could shit on when you could cheese them in bot matches).
there were also performance issues which maybe got fixed with the trial update (not sure) and of course the retarded matchmaking multiplayer which by now has killed more low-pop games than I can count. turns out people don't wanna wait 30+ minutes staring at a wait timer and using steam groups or external stuff like discord that only a tiny fraction of the playerbase uses in the first place isn't a valid replacement (even less because like I said no progression custom games).
as a whole the game was managed absolutely atrociously and should serve as a textbook case in "how to kill your game for good in a few months" when there was ample opportunity to salvage it. fuck gearbox, and fuck randy pitchford especially when, after the community begging for updates on the state of the game for months, he goes on stage and does this:
fuck that slimy weasel with a rusted rake.
but still, I kinda miss battleborn. had a lot of fun playing it and probably would've kept playing if more content got added. which never happened because gearbox did fuck all to foster and grow the community. now it's dead, and really dead when the servers go down.