If an influential person like Elon enters the crypto world it can have both positive and negative impacts. the negative impact is that the crypto market can be manipulated and the positive impact can increase the price of altcoins and provide profits for many people such as doge. but even so it is not that easy to control the crypto market because in the crypto market there are many whales.
I don't see anything positive in such affection. If doge is okay even now, most of other hyped coins almost disappeared one day after they became so much popular. I prefer projects with a natural development, it gives me more trust.