The strength of Smith-Morra gambit I am a beginning player in chess.(~1300 on chess.com/blitz: 5 and 10 minutes) And I mostly like to attack and favor fully open positions to closed and defensive. In response to e4, when the opponent plays c5, I don't have much options left. I don't like nf3, d4 too much. So, I have to resort to d4 and the Smith-Morra gambit. And, I really like this opening. However, this opening is not famous among top chess players and I wonder why. Please explain the merits and demerits of this opening apart from the early loss of a pawn to white.
Further information about openings I like and I'm comfortable with: Scotch Gambit, King's gambit. Please explain in simple terms and don't use terminology related to chess theory as I'm not familiar with those. I only play chess on chess.com and sometimes practice a few puzzles.
If you like the Morra gambit, then there is no reason not to play it. It indeed leads to open positions where white has a lead in development. Moreover, black players are typically more familiar with the main lines than the Morra, while white's initiative can be quite dangerous.

Profound analyses can be found in Mayhem in the Morra!, written by IM Marc Esserman in 2012. The forewords in the sample pages are interesting and fun to read.

The theoretical status of the Morra is that black is fine: white has enough compensation for the pawn, but nothing more.
White has better chances for an advantage in the main lines after 2.Nf3 and 3.d4. Therefore, the Morra gambit is not seen very often at the top level.