Not a wise decision if you convert all of your altcoin into Bitcoin because there are some altcoins who has a big potential to grow especially the coins that is on the top 10 although it will give you a safe long term goal for holding Bitcoin because the value will surely grow in the next coming years.
Yes, that's right, we should be able to do investment management properly. That's because there are still many altcoins that have such good prospects and don't assume all altcoins don't have prospects. let's invest smartly and choose coins that do have good opportunities in the future. don't just trust one coin, it is a bad management and try to avoid it.