It's garbage. Whatever good ideas or plot points the game had is completely overshadowed by the huge amount of grind you're forced to do, to complete the pokedex enough (e.g. catching the same Pokémon multiple times, killing Pokémon with specific type moves, seeing Pokémon use certain moves...) to progress. The catching mechanic is way too basic and uninteresting for it to be so central to the game. It's worse than any other modern open world game in existence and it's testament to the low standard Pokémon fans have when they rate this game highly, or praise it as the best Pokémon game in the last decade.