: does ethereum have a good future?
Define good future? I think so but i am not measuring good future in terms of profits.
: is it not wrong if I choose to invest in ethereum?
You are the one making decisions. Just don't make those decisions for your family or friends by investing their money. As you obviously have no idea what you are doing.
: what is the drawback of ethereum?
POS isn't really tested out yet on such a big scale. And new tokemonics could bring results we haven't really calculated. There could be new exploits bringing it down.
: why is ethereum the no. 1 ALTCOIN?
Because it has the biggest marketcap. Marketcap = circulating amount of tokens * value