I don't think many people who regularly bike in an urban environment would agree that "no driving stressors" is an applicable description of the activity.
I actually have biked around both Amsterdam and The Hague. They were both quite a bit better than other places I've been but you could still find some dodgy areas. You're right though, a flat country at sea level that prioritizes bike infrastructure is a pretty nice place to commute by bike lol
The nuance is that exercise that's baked into people's everyday routines gets done, and so extends healthy life. Exercise that requires extra time and effort gets done a lot less. This is why everyday physical activity through moving around is so important
This is part of why I like working a trades job. On a big install i can easily walk down and back up the customer's basement stairs 25 times. I get to use my muscles on wrenches and hammers. It isnt as good or consistent as exercise at a gym and I should be doing yoga more often to help with driving related posture, repetitive movements from work, and overall muscle maintenance, but I'm at least more active than a desk job.
It's also reassuring people like the dozen nervous nellies in this thread that cycle commuting (ie specifically biking through the city with traffic on a daily basis) is a net benefit despite the perceived risks.