It is easy to find such reasons now that Nokia has failed. But they ruled for a decade in part because of too many phones. They had phone at each budget range and demographic. What they missed was a move from hardware centric world to software centic. The attempts with Linux etc were too little too late.
This is exactly right imo. I was a teen during peak Nokia, and I always thought it was very clever how they had a phone for everyone, and more importantly, they really signaled to the consumer via features and marketing. I was in the UK and there was a time for a couple of years when all we talked about was football and Nokia models, we all had phones, some of us had TWO phones because we inherited an old business device from a parent etc. It was a super fun time from what I recall!