NO !!! NO!! No! Gambling is 24/7 but shopping is not.
Several of the large Hotel/casinos have shops that are not open all of the time; they have regular store hours. Places like Caesars' Forum shops, Bellagios, the shops in the Planet Hollywood Hotel Casino all have regular hours, not 24/7.
Then there is Fashion Show Mall, which is like the malls in any city with small stores and large department stores including Macy's and Neiman Marcus, is NOT open 24/7. It opens about 10:00AM and closes about 9:00 PM.
In addition, there is an outlet mall on the Strip just south of the airport called Las Vegas Outlet Center, 7400 Las Vegas Boulevard South, Las. You can easily take a bus or taxi there. It is not open 24/7 either. It's open every day but does close to 10:00 PM; I have been there at closing time.
Then there is a mall that people who live in Vegas use on Maryland Parkway, about a mile east of the Strip. Its called the Boulevard Mall and its address is 3528 S Maryland Pkwy, Las Vegas, NV. It has regular mall hours from 10:00 AM to 9:00 PM
Then there is another outlet mall near downtown Las Vegas called Las Vegas Premium Outlets, 875 South Grand Central Parkway. Its also open 10:00 AM to 9:00 PM.