The animé was always weird with that, at least for me. The animé treats most legendaries as one of many, whereas the games treat them as singular beings. And since no one ever cared about catching every Pokémon they saw, the whole “Gotta Catch ‘Em All” slogan never made sense.
That’s not really true at all though? The anime, games and manga all treat legendaries as a species with a very tiny population, with usually one specific legendary playing a role in the story.
one ep did have a Lugia with a baby though, which was weird.
(Source: gottacatchemall)