I have being giving this question a thought for days now, if other altcoins can be a threat to bitcoin especially ethereum which some folks are saying is a threat to bitcoin, and I came to understand that, the reason why other altcoins can never be a threat to bitcoin is that, bitcoin being the first and largest cryptocurrency has survived external attacks and attempted ban from government, which no altcoin has face such attack, because bitcoin has already paved way for them.
bitcoin has also overcome many social and political trials, which those trials almost led to the shut down of bitcoin, yet bitcoin gain more attention and adoption, which no altcoin has gained such attention and adoption, not even ethereum which some folks out there are saying is a threat to bitcoin.
Bitcoin has already dominated the crypto space, because it has always remained active and accessible without interruption, and to my own best of knowledge I don't think if companies like Facebook, Microsoft and Google have achieved this level of reliability which bitcoin has achieved so far, talk more of altcoins.
And I we also like to see more contributions from members of this forum, let prove to some folks out there that altcoins can never be a threat to bitcoin, because alot of folks out there are saying that ethereum will be the end and the down fall of bitcoin, which I doubt.
Bitcoin is not actually the first crypto currency. The first cryptocurrency was eCash, developed by the company DigiCash in 1990. Then there were also some other predecessors to Bitcoin. Satoshi was not really the first person to write the code, he assembled together the right parts of failed attempts of cryptocurrency creation and created the first successful cryptocurrency and called it a Bitcoin. One of the best thing that happened to Bitcoin is also Satoshi's disappearance, it made Bitcoin truly decentralized and no other coin can achieve this, ever!
Altcoins are not a threat to Bitcoin. If there is an altcoin that performs better than Bitcoin and surpasses Bitcoin, then I welcome such altcoin, I don't see anything bad into that, we are not married to Bitcoin after all.
There is not really any threat if we keep in mind that Bitcoin's code can be changed at any time if there is a full approval from the community. If any altcoin advances, Bitcoin can advance too.