What will you do if some altcoin (XMR or ETH for example surpasses the value of BTC, either in market cap or by the price of a token each? Will you sell your BTC to buy the more "valuable" coin, or continue using and holding BTC? Also, what do you think are the chances that it could happen? I would like to hear your thoughts and opinions.
It is not likely, but possible. I think it will be great to diversify. In fact, there're already very good reasons to diversify as some of the coins have very good roi.