.....You really don't know why sunfire was an issue? It was clearly explained back in the patch when it was nerfed........
And what's wrong with Bramble vest? It works absolutely great against nearly any aggressive AD toplaners except maybe gnar and darius? It's especially good against those that like to heal like Fiora, Tryndamere, Irelia and Aatrox.
Fiora even had her nerfs reverted because bramle vest was added.
The issue with old toplane tanks is that they just sat on the backline of their minions and only walked forward to when a minion was about to die, and if anyone tried to do a meaningful trade against them they would just back up 2 steps and use their abilties and the aggressor would end up taking more damage than they inflicted.
Or if they tried for harasssing as melee the tanks regen would just negate it, or they would win becase tanks often pack more power into their abilites while aggression champs often need a few seconds or auto attack resets and such.
And a reason newly reworked Fiora was so hated early on is because her 2 hit harassment actually did a lot of damage when repeated, and if you tried to follow she would also just back of into her minions and win the trade like that.
Then when the tanks got sunfire they would just sit in the middle of minion waves and you´d lose trades simply because you couldn't break their defense and deal enough damage before you as a squishy carry took too much from the tanks minions and his sunfire.
Oh and sunfire was so cheap that they would always get it before enemy could stack damage, thus you´d easily invalidate aggro AD champs even more.'
No one wants to sit and watch to walking walls try and bash eachother with auto attacks that deals like 60 damage. and very few wants to play like that as well. The tank meta is one of the most despised for that reason alone.
But that does not mean that all tanks are bad for toplane currently either, Maokai, Cho gath, singed and Ornn have all been doing well there as far as i know.