Feet are as different as fingerprints. Sometimes shoes need inserts. Sometimes they don't. Footbed design will effect that as much as lacing and inserts. Hiking in the ADK's, I mostly agree with your comments, though. With trail runners, you do not need a lot of lacing. In the High Peaks area's, you do, though. Up hills are OK. The long/steep downhill hikes are enough to mash my toes off, though. Stopping and tightening laces helps to prevent this, distributing pressure against the top of my feet. With two or three peaks per day, too much fiddling with laces to fool around more than once, tightening on the first 30 degree downhill (many are much more than that, at least for a about quarter mi.)
Inserts mainly serve two purposes. 1) Correct any walking problems (orthotic use.) 2) Comfort.
Supernating or pronating (most common) is a common problem for older hikers. Inserts can help correct these types of walking problems. Comfort is often focused around relieving impact pressures around feet, ankles, knees and through out your skeletal system. Arch problems are a common problem, too.
In contrast to using inserts and thin socks, I use a pair of extra thick wool hikers, sometimes two, and no insert. This seems to do the same job of cushioning impacts as inserts and allows me to completly fill the rear part of my shoe. (I have wider front feet than normal, narrow heels...)
Anyway, a little thought and analysis of your own feet will let you identify any problems, or potential problems, and apply suitable corrections before you head out. As I said, often, what works for one will not work for another...feet are all different. In fact you might find left foot/right foot anomalies that require a different aproach to each foot, not all that unusual.