The short answer is “yes.”
In some cases, such as the adolescent with R thoracic curve correction with pedicle screw instrumentation, kids and young adults can go back to very active sporting activities very rapidly, often within first 2-4 weeks.  We have had high-performance swimmers back to diving and swimming within 2 weeks of scoliosis surgery.
In the older adult, sometimes we have to go a bit slower, but many return to a very active lifestyle during the first year, including golf, tennis, walking, cycling, and even some running and mini-triathalons.
My father-in-law, Richard, had his L45 spondylolisthesis and stenosis fixed 2 and a half years ago.  He was back playing tennis in Florida within 6 months, and was doing his first mini-triathalon 1 year after surgery.  He has run several races since then, including the Komen race this past summer with his daughter and my wife Lori.  He called me last month and told me that he took 3rd place in his age group for a 5 k race in Florida.
My mother-in-law had her L45 spondylolisthesis fixed 5 years ago.  She was back walking 1.5 miles by 6 weeks, 3 miles by 3 months, and now walks 5 miles every day, and gardens, and dances for her retiree stage show!
She hiked the Grand Canyon with us 6 months after surgery, and the Grand Teton National Park 1.5 years after surgery.
I have seen it have a dramatic effect on their quality of life.

My friend Lou, who is a 70+ yo golfer from Pinehurst had his thoracolumbar scoliosis surgery about 10 years ago.
He plays golf 3-4 days a week, as well as bicycles and travels on a regular basis.

We do limit extreme lifting, bending and twisting especially in patients with weaker bone and longer fusion/instrumentations, but most should be pretty solid by 1 year.

Yes, most people can be quite active after spinal decompression and fusion.

Lloyd A. Hey, MD MS
https://www.heyclinic.com
Hey Clinic for Scoliosis and Spine Surgery
Raleigh NC USA