The Role of Sleep in Overcoming Strength Plateaus

I have realized that I only get about five or six hours of sleep a night because of my commute in London. I am starting to suspect that this is the primary reason why my lifts have stalled. I feel tired before I even start my warm up and my recovery is non-existent.

How much of a difference does getting eight hours actually make for a lifter? I am considering buying a Whoop strap or an Oura ring to track my recovery metrics, but they are quite expensive. Is the data actually worth it or should I just focus on going to bed earlier?

I have read that sleep is when the actual muscle repair happens, but it is so hard to find the time. Has anyone here significantly improved their strength just by fixing their sleep schedule? I would love to hear some success stories to motivate me to turn off the television and get some rest.