First, it’s necessary to be clear what one means by “training to failure” because many use the phrase to mean various different things. Including sets, indeed entire workouts, that have not a single failure (actual determined attempt to lift the weight that fails) ever happening. Instead the person terminates sets when he guesses he couldn’t get another and calls that “failure.”
Or perhaps he does attempt final reps that he doesn’t complete himself, but rather than actually employing true maximal effort to complete them himself but failing, he declines to finish or try finishing the rep by any such means, but instead lowers them or has a spotter help, and calls this “failure.”
Let’s say, though I don’t know what you mean, that by training to failure you mean continuing to attempt reps until actually failing, despite determined effort, to complete a rep. It gets stuck, you push or pull as hard as you can, and you can’t get it to go.
Now for a beginner in many exercises having quite a bit of this is fine. First, if totally avoiding it, the person will not learn the difference between the next rep being perhaps very hard but doable, versus another not being doable. That takes experience.
Second, because the weights are less it is not as draining on the system for a beginner.
For an advanced lifter it is a different story. Repeatedly (over the workout and the course of the week, etc) genuinely trying seriously to complete reps but against one’s will failing is very draining and will very much limit the volume of work that can be done.
Doing less work as a consequence of the nervous system becoming the limiting factor (which is what happens here) results in less of the effect you point out as being desirable.