Why do many players play the Englund's Gambit... It's a mistake...

I mean, I even developed a trap against this:

But honestly, why sacrificing a pawn just to play in such an awkward position?

This is actually called the Hartlaub-Charlick Gambit, which is a variation of the Englund's Gambit...

And also, I don't understand why should white play 3. exd6 when he can just reply Nf3...

Yes, but that's the only variation of the englund gambit that isn't a one-try trap and is playable.

after Nf3 black responds with Nc6, followed by Bg4 and dxe5

black is actually fine, having two pieces for the rook

and check game review, it says white is +1.51 when you play Bf4, and then +0.14 when you play Nc3

If these many players who play the Englund's Gambit going to register for the world championship or just will go against very strong bots, ok it wouldn't make much sense to play this opening but otherwise against amateur players and playing blitz or rapid, the story of it's doubtful or it should be a bad openning just they don't care IMO.

Most of us guys don't even know the full refutation and have to look at the course to know it lol.