So you haven't played it then.
No, not yet.
Absolute nonsense.
A lot of those points seem to assume you'll always have space to maneuver and never have monsters jump you in a more confined space, or be able to 1v1 the monster to exploit a weakness and never have another monster nearby to cover it. Neither of those appear to hold true for eternal most of the time.
It's the exact opposite. Normally you'd find one gun you like and just use that thorough the game. Low ammo count forces the player to use different weapons in a frantic firefight. A chainsawable enemy isn't always on hand, so you may need to use a weapon you aren't that comfortable with, and get used to it quickly if you want to survive the encounter.
I'm not so sure that "find one weapon and just use it" thing is true. Certainly in 2016 certain weapons seem to see less use like the shotgun and machine gun once players get the chaingun and super shotgun, and you'll eventually develop a preferred combat style and lean more on certain weapons, but personally and as far as I've seen in other players, it's more that they focus on certain weapons over other rather than focusing on just one.....and I wager the same will no doubt happen in eternal, with people using the limited supply of upgrade points and mods to focus on a few weapons and mods they rely on and using the others only when forced too.
In Doom 2016, at later parts of it, you had enough ammo for everything in a single fight and you could just circlestrafe around the arena and never run out. Sure, you needed to get stuck in to replenish health (and ammo from time to time), but in Eternal it's much more pronounced. You need to be aware of the battlefield, figure out where the easy targets are to chainsaw, which ones to avoid (like a mancubus), and plot your route to the walking ammo-pack on the fly, and maybe freeze the problematic enemies for a few moments with your ice grenade, or pull yourself to them with your supashooty. When out of ammo you need to dash, jump, and weave around the battlefield like a butterfly to get to the ammo that will make you sting like a nuclear bee.
It gets the player into the thick of the action much better than 2016 ever did (and 2016 was already fucking amazing at doing that)
I'm not really seeing how that translates to "no, you don't actually have effectively unlimited ammo as long as you push a button every once in a while". That's just saying it's sometimes a bit tricky to hit the button.