82 industry though, geez. We might make like, three, total.
That's perfectly fine. These are capital ships meant to be supported by a modest number of escorts (almost certainly Stingrays) and act as a titan on the battlefield, forcing either a massive concentration of force for defense or a massive concentration of force for attack.
Consider the alternative: we'd have just as high an industry cost in exchange for faster warp speeds and a secondary hull, but less capable tactical systems and weapons coverage.
This was always going to be expensive. But here, the cost is going to pay for a juggernaut that will make the Romulans have to deal with a threat their fleet composition is undoubtedly not prepared for. And simultaneously, it will turn a lot of heads among the other polities in the sector, showing humanity's industrial capability (very impressive for such a young species) and its temperament (it could build some rather powerful dedicated warships but only does so when the need is forced upon it--it built a series of large exploration vessels before it built a warship larger than a light cruiser).
And if humanity can produce something like this despite its inferior technology when seriously provoked, what will it be able to do when its technology and industry catches up? And if humanity's natural temperament is friendly and somewhat idealistic (it was surprisingly merciful towards the pirates that attacked it, and didn't immediately declare war on Romulus when the Discovery was destroyed by a Romulan attack, and is only going full war mode on Romulus after Romulus tried to destroy Earth with a suicide run with cobalt-nukes without any provocation), well, there's a lot of incentive to play nice with them.
Humanity doesn't have to be a bigger or more powerful player than the Vulcans or the Andorians. The notion of a kingmaker means that it only has to be powerful enough to tip the scales--and if it would rather make everyone co-kings, that's still a safe net-win for everyone involved.
My opinion on the royal navy is universally negative.
Universally? I mean, they have/had some of the best ship names.