Should you purify Shadow Regigigas in Pokemon GO?

Regigigas is making a comeback in Pokemon GO, and this time, it is available in Shadow form.

Analysis] Shadow Garchomp as a raid attacker: An upgraded but specialized Shadow Mamoswine - Pokemon GO Pokebattler

Frustration, Pokémon GO Wiki

Should I purify or leave as shadow? It's my first Regigigas. I've never been too knowledgeable about benefits of Pure vs Shadow. : r/pokemongo

Pokémon Go Shadow Pokémon counters, how to beat Shadow Snorlax and how Purified Pokémon work

What is the best shadow Regi?

Should you purify shadow Regice in Pokémon Go? - Gamepur

Should you purify all your Shadow Pokemon?

Pokémon GO - Team GO Rocket

Pokémon GO: The Best Pokémon Of Every Type

Looming in the Shadows Guide, Pokémon GO Hub

I know people say not to purify : r/pokemongo