Do you agree with this?

[Woodznutz]

Doctors advise getting up if your back hurts while resting because it can help alleviate stiffness and discomfort caused by muscle tightness and poor posture. When you lie still for extended periods, your muscles lose flexibility, and upon standing, they pull on the spine and surrounding tissues, causing pain. Getting up and moving can help release the tension and improve blood flow to the affected area. Additionally, maintaining regular movement can help keep your muscles flexible and strong, reducing the risk of stiffness and discomfort.
Medical News Today

And how does this comport with the above?

Healing​

The healing process typically involves several stages, including inflammation, tissue repair, and remodeling. Pain can be a part of these stages, signaling the need for care and attention. For example, during the inflammatory phase, pain may be more pronounced as the body works to repair damaged tissues.
kimawellness.com

So, it seems to me if one gets up because of pain it actually interrupts the healing process, which can itself be painful.

I recall the intense discomfort I felt all over during a three-day complete fast back in the day. I could have relieved the misery by breaking off the fast, but I wouldn't have received the benefits of it. I stuck it out and the misery abated and when I did break the fast, I was a new man. The best three days of misery I've ever experienced.

 

[lg325]

Yes, just from my personal experience at being laid up for ten years.

 

[shockedcanadian]

Doctors advise getting up if your back hurts while resting because it can help alleviate stiffness and discomfort caused by muscle tightness and poor posture. When you lie still for extended periods, your muscles lose flexibility, and upon standing, they pull on the spine and surrounding tissues, causing pain. Getting up and moving can help release the tension and improve blood flow to the affected area. Additionally, maintaining regular movement can help keep your muscles flexible and strong, reducing the risk of stiffness and discomfort.
Medical News Today

In my experience, except in the extreme case of a critical injury for which movement could cause permanent damage; when something is hurting, movement brings blood to the area and keeps the body well oiled.

The old saying "slow down, live longer" only applies to heavy physical workload (which I have experienced at times in my life), especially with age. In general, once you slow down, your body decides it does not have a purpose anymore.

 

[Natural Citizen]

Doctors advise getting up if your back hurts while resting because it can help alleviate stiffness and discomfort caused by muscle tightness and poor posture. When you lie still for extended periods, your muscles lose flexibility, and upon standing, they pull on the spine and surrounding tissues, causing pain. Getting up and moving can help release the tension and improve blood flow to the affected area. Additionally, maintaining regular movement can help keep your muscles flexible and strong, reducing the risk of stiffness and discomfort.
Medical News Today

It's been chilly here at night, so last night I threw a log on the fire place and laid flat on my back with two fluffy pillows under my head and watched a movie.

It felt great just laying flat on the floor on my back.

Some relevant reading...

Is Sleeping On the Floor Good for Your Back? | NSC

Searching for answers regarding if sleeping on the floor is good for your back? If so, you're at the right place. Learn more, right here!

neuroandspineconsultants.com