Early into the expansion, I would agree with you. The other two specs were undertuned and clearly lacking. Multiple waves of buffs down the line, though? It’s all about player perception and as shown on the warcraftlogs, they can perform in the hands of the right player. It’s just that the playerbase is stuck in the past and didn’t give them a proper go after all the shifts in tuning.
I’ve seen somewhere that the changes are 7-8% on single target alone. More than that on AoE, thanks to the flamestrike+flamepatch changes. Just a 8% dip in single target alone would be enough to bring it to meme-spec tier. You might not realise that as a challenger-level PvPer who didn’t clear Nathria heroic this many months into the tier, but in mythic raiding fire is already shown to be mid-pack on fights that do not favour it. Nerfing it will bring it somewhere to the middle on the few fights that favour it, and all the way to bottom-tier on the ones that don’t.
In m+ I’d expect it to fall out of favour in random groups for key levels below +20. The nerf it is receiving is way more than 5% in both single target and AoE, so unless you are in a premade group that can afford pulling multiple packs whenever your combust is ready, either frost or aracne will be able to perform better than fire.
You don’t see it much on the ladder right now since it is quite dead, but frost is starting to see more representation in caster cleaves and turns out to be replacing fire in stuff like MLD. A frost mage team nearly won the AWC finals. If that is not proof that the spec can perform well, I don’t know what is.
What utility? Dragon’s breath is the only thing they have that the other two specs don’t. That comes at the cost of their slows being inferior to the other two.