I bought my E-bike as an alternative to using a motorbike to commute. I'd never considered cycling in the past as i didn't want to turn up to work all sweaty and have to deal with changes of clothes etc.
When i bought my first e-bike it was a gamble, i thought it might not be for me or i'd only use it in fair weather ,but i couldn't of been more wrong. I've only missed about two days all winter so far and although you definitely still get a great cardio workout , you can dial it back if you overheat and let the motor do some work. Once you hit town they are also fantastic when you are stopping and starting all the time and you don't need to be going through the gears all the time.
If i cycle for leisure though, i still take a normal bike. I wouldn't say its 'more fun' , but if i have no time constraints on where i need to be then i don't really feel the need for the e-bike.
I think they both have their place and both are definitely still fun.