Curiosity: Getting to goal without exercise

Definitely not. I've lost 72 pounds and tried walking 2 miles for the first time in a few months and I was so out of breath, couldn't keep up with my friend, etc. And the next day every muscle in my legs were sore. But the weight loss has been over 13 months for me so it was pretty slow. Maybe people that lose it quicker notice being lighter on their feet at least.

Just losing weight won't change your physical fitness.
I've had a few points in my weight loss were I couldn't exercise (longest was c-section recovery that took longer than normal since it started to reopen). I had to eat less calories for the same rate of loss, I was tired a lot and my mood was pretty much crap.
For me exercising equals better mood, more energy, preserving muscle (modest deficit + lifting+adequate protein intake) and more calories available. Even a simple walk is nice and that's actually what I originally started with. Just walking. Eventually I started running and strength training (which eventually led to lifting) because I wanted to improve my fitness. Would be lighter have made running easier, maybe, but probably not to a noticeable extent since it would have been something my muscles weren't used to doing. Either way running even a mile is something that I needed to work up to (my starting point was only being able to walk a quarter of a mile or so before needing a break).

I lost around 50lbs with no exercise. For me, I didn't have the aches and pains doing regular activities anymore, after losing the extra weight. So losing the weight, even without exercise, helped improve things. I also have a lot more energy now, sleep better etc. without exercise being a factor.