First Shiba Inu isn't a competition for Dogecoin, rather Shiba Inu is a coin that capitalized on the fame and promotion given to Dogecoin by a soon to be an Influencer Elon musk, and being one of the first to see how profitable it is to mimick dogecoin coin, Shiba Inu felt its a close competition to it, now I think Shiba Inu cling on that advantage is fading off. So many other new project has taken the same part as Shiba and I still believe they all won't last long.