I guess we can just agree to disagree since you probably wont change my mind and I won't be changing yours. Thanks for replying though. The more I look into this Poke, the more he seems like a viable option over Jirachi in certain sets since he also has winning match ups against Garchomp and Glisscor
OK here's my thoughts on why Bronzong is barely viable:
I fell asleep typing this.
1. It has no reliable recovery
Jirachi's main niche, when I consider using it on a team, is a WishPasser that doesn't get blown away by Psychic- and Fairy-types. It can reliably scout for moves with Protect, and doesn't lose me a lot of momentum after using Wish, as it can U-turn out. Bronzong, in the other hand, has no reliable recovery aside from Leftovers, meaning it can't reliably check Psychic- and Fairy-types.
2. It is passive/has no offensive presence
Toxapex is passive as well. Why is it ranked so high? Basically because of its better bulk, superior typing, amazing ability, and reliable recovery. Bronzong heavily relies on Toxic and Gyro Ball to do any sort of damage, i.e. You get walled by Heatran. Aside from that, it invites in plenty of top-tier threats in, like Ash-Greninja and Mega Mawile. Sure, you can say they threaten Jirachi too, but they all fear being crippled by Body Slam paralysis or getting U-turned on.
3. Why are you using Bronzong to check Ground-types?
You say it has winning matchups against Garchomp and Gliscor. Probably Garchomp only, since it doesn't bring anything to hit Bronzong super effectively unless it's Fire Fang Mega Garchomp. Landorus-T is bringing stuff like Smack Down, Knock Off, or even Gravity to improve matchup against Celesteela or Zapdos, which have become more common since the Zygarde ban (or at least for me). Bronzong also doesn't beat Gliscor, no matter its set. Stallbreaker sets can Taunt you and use Knock Off, rendering Bronzong with no recovery; SD sets use you as setup fodder and beat you 1v1 with Facade or Knock Off (unless they're EQ+Ice Fang). If you really wanted a better matchup against these I'd just go with Celesteela or a Grass-type, which, in addition to being more viable, isn't weak to Pursuit trapping.
4. It's outclassed in practically every way
As a special wall, it's outclassed by Jirachi, Heatran, and Celesteela, which all have better utility. As a trick room setter, it's outclassed by Cresselia, which has better bulk, Moonlight, and support with Lunar Dance; Uxie, which can use U-turn or Memento after Trick Room and Stealth Rock to pivot out; and Magearna, which has decent bulk, a better defensive typing, more offensive presence, and a great movepool to back it up.
tl;dr While I think Bronzong is a Steel-type that can compress several roles, its lack of reliable recovery, vulnerability to Knock Off, and being heavily outclassed by a majority of other Steel-types makes it a very niche and would be my last choice for consideration when teambuilding.