Depending on the specific “boonie”, there could be spotty/no internet, few/no service companies, few/no medical specialists, few/no decent restaurants, limited/no road services (think snow)...
Except for a couple of years in my late teens when I got my first apartment, I have never lived closer than 30 minutes from town. I have never had any desire to live in the city.
Our current home is about 30 minutes from the closest big grocery store, my local doctor office, or decent restaurants. Ironically, I still have a Home Depot about 15 minutes away, and get broadband cable internet.
I've never minded driving to town for groceries, as it's typically only once a week. But I could always order online and have them delivered if it comes to that. Or, I could hire someone to take me on errands.
We built our home to be our forever home. Single level, roll-in curbless shower, 36" wide doors throughout, etc.
As for yard work, when using the walk-behind mower gets to be too much I'll buy a rider. When I can't manage that, I'll hire out or ask a family member.
We do get snow up here on the mountain, but it usually only lasts a day or two. When we don't need to get to work anymore, we'll just wait it out and do our shopping after it melts. We're getting less snow each year anyway with the changing climate.
Generations got by just fine living much more isolated than I am. Just because I can live 5 minutes from a doctor doesn't mean I have to. Yeah, I might die in a situation city slickers would survive, but we all die sometime.