Ask any Amiibo collector (or former enthusiast) and you'll likely hear the same things. They'll tell you that the process for pre-ordering and acquiring new releases is broken. Nintendo isn't producing enough to fill the supply chain. Things need to get better.
As a consumer, I wholeheartedly agree. I've almost stopped collecting them. I couldn't help but pick up the lone Girl Inkling Amiibo that was available alongside my Splatoon purchase. I did turn down Pac-Man, though.