6.5 Grendel was designed specifically as an AR-15 variant cartridge. https://www.alexanderarms.com/history/
OP, in summary, says Grendel has its own advantages separate and apart from AR-15s mostly because of how it reloads.
With cheap steel case, Grendel, in my opinion, was the no-brainer choice for AR variants. With that gone, other choices come into play for AR variants.
For short-action bolt guns, Grendel is even more of a niche cartridge. Reloading-wise, Grendel presents some good advantages, as OP points out. Shooting-wise, other cartridges out perform it, with 6.5 Creedmoor leading that pack.
Grendel's low recoil comes from it shooting (relatively) light bullets at low speeds. That necessarily creates its own ballistic issues.
To me, where Grendel really shines is as a short-range hunting cartridge for compact, i.e. short-barreled, suppressed rifles.
OP, in summary, says Grendel has its own advantages separate and apart from AR-15s mostly because of how it reloads.
With cheap steel case, Grendel, in my opinion, was the no-brainer choice for AR variants. With that gone, other choices come into play for AR variants.
For short-action bolt guns, Grendel is even more of a niche cartridge. Reloading-wise, Grendel presents some good advantages, as OP points out. Shooting-wise, other cartridges out perform it, with 6.5 Creedmoor leading that pack.
Grendel's low recoil comes from it shooting (relatively) light bullets at low speeds. That necessarily creates its own ballistic issues.
To me, where Grendel really shines is as a short-range hunting cartridge for compact, i.e. short-barreled, suppressed rifles.