Meditation is a practice, you practice to keep your mind "clean" and don't clutter it with unnecessary thoughts, worries, etc. If you master this skill, you will require less sleep. And then you don't have to be sitting on the floor all the time, you can just live your life without cluttering your mind all the time. So it is ultimately more efficient than cluttering your mind all day and then needing lots of sleep. But it does take some initial practicing time before you reach that state of mind. But with all things, if you put some effort in beforehand, you can reap a lot of gain afterwards. Doing this practice for about 20/30 minutes every morning can already quickly bring great improvement to your daily life. If done right that is. It's easy to do it wrong also, and then it can not bring any benefit. Sometimes it's necessary to first work out some traumas before you start a serious meditation practice. Sometimes meditation actually helps you work out traumas. It all depends on the person and situation. For some people guided meditation works great, other people rather just sit in silence. It doesn't really matter, as long as you find something that works for you.

See it like exercising: you might think that spending time on exercising takes away time that you could spend on doing useful things. But it actually gives you better health, making you function better in your daily life. So it enables you to do things more efficiently. And you'll feel healthier, better, happier. So ultimately you gain from it.

I think the point would be if you could replace ~8 hours of sleep with ~1-2 hours of meditation. I very much doubt it's a like-for-like replacement, but it might go some way to reducing the need for full sleep, e.g. 2 hours meditating + 2 hours sleeping = 8 hours sleeping.

“You should meditate 10 minutes each day,” the teacher said. “But I can’t find 10 minutes every day!” said the student. “Then,” replied the teacher, “you should meditate for 60 minutes each day.”