Old school milsims actually were pushing the tech envelope. Novalogic were the kings of it and went all in on voxels for good or for bad (mostly bad). And it let them do VERY large worlds with a lot of entities being actively simulated at once with an art style that could run on hardware of the era.

And even the OFP/ArmA era were similarly beasts of games that mostly just took advantage of uniforms (that thing soldiers wore before cod and battlefield decided they wanted to sell skins) to reduce the textures that needed to be in memory.

The reason newer Ghost Recons don't actually play like Ghost Recons is that they aren't actually milsims anymore. They are movie sims. They want you to feel like you are Jim from The Office getting froggy with all the terries. You can see the same with the Rainbow Six games where they went from tactical room clearing to fighting off hundreds of terries in a single small house in Vegas (good game) to outright not even having pve anymore in Siege.

Which is the same reason Battlefield keeps trying to make people think it isn't a Battlefield game whereas cod increasingly tries to become one. Major studios make games that sell well by remaking games that sold well.

Which is why publishers like MicroProse (modern and historic) are awesome. They make games that others aren't making or that others aren't doing a good job of. Sometimes that is a ridiculously complex mech game that nobody understands and other times you get something like High Fleet that is almost universally praised for its accessibility and style while also being streamer candy for the ones who try it.

But, at the end of the day: Just because a game isn't made for you doesn't mean it shouldn't be made.