That or the alien will simply scour all life from the planet and then strip mine it for resources. They don’t even have to be more intelligent than us. Suppose they were roughly equivalent to human intelligence but had an insect-like eusocial behaviour with a billion year old culture. They could be far more advanced than us simply due to the availability of time.
Yes and they’re yet another collectible product that exploits the psychology of a subset of people who compulsively collect things. I put them in the same category as gambling and note that there’s a lot of crossover with these things (loot boxes and CCG booster packs being prime examples of a gambling and collectible combo).