While I personally wouldn't change my 6 mile commute decision based on if my bike had an assist (6 miles is an easy bike commute without assist to me), if it actually would make a difference to you then get it. I get the impression from many people who have gotten an ebike that they end up using it more than they thought they would. I would get it for the benefits of biking even if the reduction in car costs does not mitigate the full cost.
This is quite true. My experience has been that I ride a lot more with an ebike than I did with a pedal bike, I use it for a lot more things, and other people I know who've purchased electric bikes do the same thing. This is one reason I tell people to get twice the range of their commute in terms of battery - it's almost certain that they'll end up using it for way more than just a commute.
They're much more of a car replacement than a bicycle is, especially if you don't work in an environment where showing up sweaty is considered acceptable.
I think that the variance in time it takes to get to work would be least by ebike and greatest by car - any bike would be less subject to traffic than a car and an assisted bike would be less subject to personal energy level than an unassisted bike.
This is why I got into electric bikes. It's mostly immune to traffic, and is also heavily wind-resistant. Going to work in a stiff headwind is annoying, not "Wow, this will take an extra 10 minutes and I'm going to be soaked in sweat for an hour."
And it's literally faster than driving during normal traffic. That's pretty nice too.
No. Just ride your damn bike. You'll get fit and your bike skills will get better each day. Give yourself sufficient time to deal with a flat tire [15 mins is enough] on the way to work.
You don't need an e-bike to go 6 miles.
You know, that attitude has been present for the past 30 years or so. "Just suck it up and bike!" It hasn't really done much to change the primary nature of commute in the United States, at least (still single occupant car). I get that some people love biking as a form of recreation, but not everyone does.
I think it's well past time to try, "Hey, electric bikes are a great way to get around instead of a car." If someone wants to ride centuries on the weekend and commute in lycra, awesome. More power to them. But that set of attitudes has done more damage to bicycles as a form of transportation than anything else I've seen.
So, yes, I will encourage people who are driving to get electric bikes. Getting out of a car, into the morning air and being active, even if it's less exercise than a pure pedal bike, is still a big win on pretty much everything that matters.