[sn9]

The question isn't if people have time for elite levels of training.

The real question is if you can get more done in the time available to you with HIIT or LISS cardio.

If you're sufficiently time constrained, HIIT will win.

But past a certain threshhold, LISS will always allow you to perform a greater volume of work with lower recovery costs and lower injury risks and, consequentially, greater benefits to health and fitness.

[sundvor]

I think you last point is very important.

For overall health, going for "failure" in weight lifting appears to be the delusional to me; it's much better to lift at a consistent, repeatable level than to greatly increase the risk of injury chasing short term gains. When injured, your volume is going to be zero.