I think we have different grocery habits.
Food, beer, and cat litter would be too heavy for a bike.
I don’t know how often you’re buying cat litter, but carrying food and beer in a pannier on a pedal-powered bike is perfectly reasonable, let alone an ebike
I live about 3 miles out of town, fortunately directly on a rail trail. I ride my e-bike in to town to get groceries weekly. I have saddlebags on the bike and I pull a kids trailer with the seat folded down and have never run out of room, or had issues with weight. Sometimes I'll even get a few bags of water softener salt. I have a fat tire ebike (aventon), it's pretty sturdy. I've got about 2k miles on the bike, I'd guess half those are from grocery runs.
For years we’ve been grocery shopping with e-bikes and a burley flatpack trailer. The trailer can hold 50kg/100lbs and we used to live up a steep hill. No problem at all. If it fit on the trailer we could haul it back. 52V e-bikes limited to 25km/h.
You don't think a family of four buys 'food' ? I also get beer occasionally, although sometimes I get it from the corner store a few blocks away.
I do get kitty litter with the car on the occasional trip to Costco because I'm not set on using the bike for every last thing. Just that the eBike makes a lot of things a lot more convenient.
A beer run on an unpowered bike isn’t too bad. 2 six packs and a few snacks is just fine.
Important note: if you put a beer in the bottle holder, give that one away and take another for yourself.