For me I got an e-bike when they finally started making light, low powered gravel e-bikes a few years ago.
I still wanted to get a good workout in, but I wanted to ride further, faster and more often, while also maintaining the handling of a lighter bike.
Ride further: The area I live in has hundreds of miles of very well-maintained dirt and limestone trails that twist and turn deep through the woods. If you've ridden both pavement and dirt, you know that dirt requires more effort and concentration to ride on. With my old non-powered bike, I could do around 30 miles before getting tired. With my light gravel e-bike, I can do double that, reaching trails that I was never able to before.
Ride faster: With my old non-powered bike, my average speed on dirt was about 14.5 mph. With the e-bike, it's 15.5 to 16 on the lowest power setting, with some rides hitting 17 on the medium power setting. Doesn't sound like a huge difference, but it is. I can traverse a much longer distance in less time, which means I can go for a ride in the early morning and be home in time for lunch, and also have time (and energy) to cut the lawn for an hour.
Ride more often: I retired recently and now have more time to ride. Sometimes I'll go for a ride 4 to 5 times per week since I can just bump up the assist if I feel my legs getting fatigued from my other previous rides. Also, I don't care so much about the wind direction. With my old non-powered bike, I would always check the wind direction and speed, which would then determine what trails I would ride on. We get a lot of high winds around here, that can be 20 to 25 mph, with gusts into the 30's, especially in spring. With a non-powered bike, that's fun in one direction, but an absolute nightmare coming back. To make matters worse, the stretch of trail leading back to my house runs east-west and is uphill for 8 miles. The wind around here blows east 90% of the time and my ride home is west. So, if it's windy, I'm not only fighting the wind, but also riding uphill. With my e-bike, I don't need to worry about that so much and can go wherever I want, not caring too much about wind direction or speed.