The Grob Gambit… thoughts?

Objectively speaking, the Grob Gambit isn't that good of an opening. It does however, like many gambit openings, have a lot of traps and tactical patterns which the unstudied player may fall into. The higher rated players who tend to study openings will probably know enough to make an opponent attempting the Grob to regret trying it against them, but every now and then someone will try a silly opening like 1. g4 just to see if the opponent remembers their opening theory.

the grob mainline with 2.bg2 is totally busted. by the above. But what makes it even worse.

the saddest thing is, even if the main trap works, black is still slightly better since white's development is so crooked. 
only way to sort of make it sort of work is basman style with 2.h3 where white often delays bg2 significantly. looking at an eval bar is kind of traumatizing though
the problem with grob is. 1. it significantly weakens the kingside even if you dont castle there. 2. unlike 1.b4 which can count on the help of an eventual c4 (and further support from qb3 if need be), white can virtually never play f4 to support the g-pawn due to the fatally weak h4 square for the black queen.
Basman was able to get away with it, because he was a creative genius that actually studied his lines and it was the pre-computer era but now, with cloud engines, the opening simply stands no chance.

they are plenty of ways to get an offbeat game without totally sacrificing objectivity. you can play 1.f4, or 1.b4 or offbeat lines of 1.g3 among other options.

The Spike Attack with g5 and h4 is another try, but it is similarly unplayable if Black has spent 10 minutes looking at it before the game.