Err, they filled a niche just like the Tesla did.
100km of range was enough for plenty of daily usage scenarios.
Telsa didn't have the range because it was better engineered or had magical new technology, it simply cost a crap load more because it has a ton more batteries and was designed for a different market. Tesla's were and still are firming in the luxury car catgeory, screw the cost. Even the Model 3 barely scraps in under the Australian luxury car tax threshold.
What Tesla did was challenge the whole perception of electric cars, and they succeeded IMO.
Barely.
They had to beg existing signed up owners to pay more to keep them afloat so they could deliver.
They were like a week or something away from going bust, just like SpaceX. Both companies ultimately survivded to florish, but it was touch and go.
They have good range too, much better than other pure EVs on the market, yes they're relatively expensive but nobody else was offering long range versions of their EVs at any price. Why does this matter? Because EVs had a reputation for being slow, under powered short ranged toys and somebody needed to break this perception by releasing something that is so far in the other direction that it completely shatters the stereotype.
Yes, that was ultimately a winning formula for them.
Nobody can make a blanket statement that EVs are slow and underpowered
That's ultimately not what held EV's back though. It was making them look and feel like a normal car, and givign them a usable range.
Again, the LEAF was quite successful because of those reasons. Range and performance was adequate enough, and it felt and drove like a normal car pretty much.
It's no surprise that both ends of the market have been successful.
Tesla with their high priced, high performance, long range and flashy status symbol.
And Nissan and others with more affordable cars good enough for everyday use.
Make no mistake, the Nissan LEAF and others would still be sucessful is Tesla had failed, it was simply time for the EV revolution.