Steelers absolutely still run a 3-4, as do the eagles, rams, chargers, etc.
Yeah the 4-2-5 is cool and all but go run that vs a 2 tight end set and get obliterated.
You need a good base defense regardless of if it’s a passing league or not. You running a nickel defense vs 3rd and short or 3rd and goal?
You should absolutely put more talent on your nickel D since you're in it for the majority, but you also have to have a good base defense, no question about it.