I don't think so because how they will earn from it if the price is stable? If investing is their only way to ear will It's too bad for them. Well, I don't think it's a threat for bitcoin since it still has a lot of investors now since the value dragging down so investors might earn some profit when the value rises again. Stable coins are the same ecosystem with fiat I guess.
Fluctuations and volatility are two things that will support the trading and investment system. Both of these things work well and also not because they can make you lucky and also lose. Without fluctuations and volatility, I think we only save money there, which is the same as saving money in a bank or vault. I think without these two things, trade and investment are no longer attractive.