I'm not sure how this works as a counter response. OSRS is a perfect example of how magic is useful in bossing. Zulrah is a huge deal. The best money maker in game is based primarily on your magic offensive bonus. Kraken requires magic too. Barrows as well. And by the way, I tried barrows on Alora with max magic and max melee. Max melee was way better.
The argument is that Alora isn't missing much in terms of magic use in PvM.
1.)The biggest thing it is missing is Zulrah. Though you can still use mage there just fine, it's just not meta due to the overtuned BP.
2.)Barrows CAN be done just fine with Mage on Alora, just due to how quick it is to get to barrows on RSPS, your typical osrs meta won't apply here.
The reason it is meta on osrs, is because you typically wear graceful/mort legs 4/trident & pray flick, which allows you to do many trips, versus melee/range which is faster but requires bonuses to do effectively (using trident allows you to practically 1 item).
3.) Kraken can be done with range on osrs but kills will take 15x longer due to them being extremely resistant to range type attacks, therefore making range not worth.
4.) Scorpia meta is welfare monk robes + trident, otherwise you'd BP it, but if you're pked gg your darts thus making it not worth.
Overall, mage lacks usefulness in PvM in osrs in 90% of scenarios due to slower kill times.
The reason you DO mage is typically to save money by using trident.
I feel like you haven't ever PvM'd on RS to understand the uses, because what your suggesting is minimal.
Even if BP is to ever get nerfed, it doesn't stop the fact that melee will still be more meta in 90% of scenarios than mage ever will be, due to how teleports work.