There are significant semantic differences between 1) lifestyle, 2) job, and 3) vocation. I would suggest entrepreneurship is more along the lines of #3, than 1 or 2.
Lifestyle smacks (to me) of a particular level of material consumption, even though the bare term might be defined as "way of living or doing things". Your lifestyle can change...or be changed because of forces outside one's control.
Job is a temporal practical outworking of a paid role, and has little to do with passions, real purpose or calling.
Which brings me to vocation. The root of the word has to do with "calling" - and I believe humans are called to fulfill a purpose. This deep underlying purpose drives us despite a particular lifestyle, or the job I may or may not have at present.
A true entrepreneur discovers they have it in the blood - they are driven to create ex nihilo, to hazard the chaos and uncertainty and unreasonable risk and mounting odds against success or even finding sufficient customer validation or build an MVP. They must because it is hammered into them like purpose and passion and vision.
The sacrifices you mention are all real. And they hurt. When a founder tells me, "It's been really...hard", I know in that little pregnant pause how hard it has really been. And until you've really been there, you can't really understand. But once you've shared in that kind of "hard", that level of sacrifice and risk, it's kind of bonding and brotherhood.
It's a calling. Sorry to wax poetic on this one. Hope this makes some sense.