Many people think bitcoin is blockchain 1.0 and ethereum is blockchain 2.0. But i think it is just the points they made to sell the coins which claim to be 2.0 or 3.0 to the people new to crypto, because it will sound like those coins are more advanced than bitcoin. But i tell you this:

Bitcoin maybe old, but it is one of the most well developed coins out there, and has been tested for the longest. If some crypto claims to be better than bitcoin or ether, or going to be the next bitcoin, look for the reason behind that claim. Is the tech that advanced? Is the idea realistic?