I'm not sure what you mean by stable altcoins? What is it like? I know only one altcoin, which does not change the price - it's USB (Tether). But there are reasons
What a brilliant genius idea this coin, just the coin that needed to enter the market, not sure why it was not created before to be honest, but yeah that's the only coin I can think of with a stable price on the market.
yes, the coin is good because its course does not change. but it is a long time ago, and altcoyins still depend on bitcoin. so with the new arrivals of such coins nothing will change