Like many previous ETFs topics, people always question ETFs, some think it will have a negative impact on Bitcoin and don't like the appearance of ETFs...but the problem is we can't do anything to prevent it. So it really is a waste of time when we spend time talking about things we cannot change. And in my opinion, the existence of Altcoins will have a positive and negative impact on bitcoin, and what we need to do is adapt to it because we won't be able to do anything to change that even when we don't like it.
I'm not against predicting or speculating on the impact of new things like ETFs could have on the price and Bitcoin as a whole. And I'm all in favour of trying to identify any future threats that ETFs or altcoins can pose to Bitcoin, so we can maybe act to prevent such etc. But asking whether Bitcoin would be better off if no altcoins ever existed is a pointless thought exercise at best with no value to it. Unless people get entertained by having such discussions, then it's OK I guess.
Altcoins serve as the biggest competitors for bitcoin, but if we analyze it closely, altcoins are somehow promoting bitcoin because once people experience losses with altcoins, the next thought will be they won’t no longer trust altcoins but will focus on bitcoin instead. So this is quite a blessing in disguise for bitcoin because without altcoins, people will not be drag into the crypto space to invest, so people have known bitcoin because they were disappointed with altcoins whom they trusted at first.