Both options make a lot of sense to me. Taking with the pawn is the 'not positional move' since it ruins the pawn structure and the black king will not be safe on the kingside anymore. However, it makes sense from the dynamic point of view since the g-file can be used to attack. The combination light squared bishop + rook is very dangerous for White, and the black king in many cases can castle queenside. This is an extremely important moment for White. Think carefully and find the best move!
Fantastic move by Nepo. With this move, the Russian Super-GM guarantees safety for his king for the rest of the game.