On the bike/e-bike/e-cargo-bike spectrum, any of those can replace some car-trips and as you progress along that spectrum the potential for car replacement increases. Getting people out riding more and replacing car trips is great, but it's car-replacement that interests me the most rather than trip replacement.
We've been a two-car family forever for most of the same reasons that many families are, so I fully sympathize and understand - no stones being thrown here. It boils down to cities being designed badly and making it very challenging to meet your needs without a car. Even if the second car is completely redundant 95% of the time, that 5% justifies the second car for many people. For example, if I'm on a road-trip with one car, or just out for some reason, my wife would feel very uncomfortable not having a car available to her. That's a scenario that only occurs once-in-a-while, and when it happens the need for the second car is rare, so it's like a 10% chance of needing/wanting it during a situation that only happens 10% of the time (10% of 10% = 1% actual need)
Now we've finally agreed to drop down to one car (when the older one dies). I would have liked to do this a long time ago, but it definitely would have been a one-sided thing with me making all of the concessions. Fortunately, philosophically I've come around to wanting to minimize the priority of cars in city-life and design, so I try to do everything I can without a car anyway, at least around town. Inter-city travel is basically car-only in Canada thanks to 50 years of under-investment and active destruction of all alternatives except flying.
The things that have made the difference for us to drop down to one car are:
1. We live close enough to grocery stores and other amenities that we can walk, although it's not as close and dense as it should be. The conspiracy-theory view of being able to walk to the things you need is mind-boggling. As much as our area needs so much improvement, our bike and transit infrastructure is far better than average for North America.
2. We're both FIRE'd, although I'm essentially working full-time at a fun FIRE job (at a bike shop). I can bike to work in pretty much any weather. Being a bike shop we have staff bike hooks indoors, a shower, a bike wash station, rental bikes we can borrow any time, etc. so it's definitely playing the game on easy mode. Additionally, our child is now 14 that simplifies a lot of things compared to the kindergarten plus two full-time jobs phase of our lives.
3. We have a decent car-share in the area with one of the parking spots about 500m away.
4. I had my wife's bike converted to an e-bike and am working on extending her riding season (I'll ride in any weather but she won't) with pogies and possibly a light helmet with a full face-shield (her eyes water in the cold and wind).
5. I'm swapping out my old commuter bike, "The Frankenbike," for an ideal commuting machine (not an e-bike, but internally-geared hub, belt drive, and dyno hub so lights are always on the bike and don't need charging).
6. We'll probably add a cargo-bike to the fleet that will replace a car trips for most errands. Eliminating the cost of a second car can fund a car-share membership, multiple bikes, the occasional taxi or car-rental with lots of money left over.
The number one factor in being able go car-lite is location. City design and building codes are what influence the number of people who have access to a location that facilitates it.
I recommend taking a big-picture view of the whole situation. Perhaps getting the e-bike will combine with other factors to go help you go more car-lite (I know that wasn't the question you asked in the first place). Aside from all of that, if you and some family members get out more rides than you otherwise would have then that's a win.
