I would laugh my balls off if Dogecoin became the defacto stable coin used for getting in and out of other coins. What a complete FU to the world that would be.
It is absolutely no brainer to use the Doges as USDT, I can't even imagine the situation. l'm not too fond of Dogecoin, but it seems to me Dogecoin can be more useful than another. l understand your opinion, nobody can know, what will happen. It is only speculation, but 80% right speculation in my humble opinion. Personally speaking, Dogecoin has more advantages than some altcoins. De facto the crypto experts have more reputation among the crypto influencers and their words are heavy than average crypto traders. In case of collapse in stable coins which is inevitable, the situation will become worse but let's hope for the good and forget about the dominance war among the stable altcoins. Doge is the last option for converting the trading profits to the more stable coins in my opinion.