It's basically luck, though.
Are "Brilliant moves" in computer analysis just any decent sacrifice now?
I don't think I ever had one. Once my opponent had, but only to throw the game away on the next move. Clearly not brilliant

An engine has a very objective metrics for the notion of "very hard to find", unlike human beings. I also don't think that a brilliant move has to be counter-intuitive.
While it is true that some obvious-yet-dicey move could be "brilliant", it's brilliant because the calculation required to verify it is too daunting. Tal "intuitively" made many brilliant moves which were not fully calculated out in advance. So perhaps a "brilliant" move is that which significantly increases your chances of winning (or drawing), but which is very hard to find or very hard to calculate?

I had a Brilliant move once. Im a begginer and I have played about 800 games so far. Its quite a rare event.

i have got several brilliant moves in my games, although i dont know why. they were obvious moves anyway

I think I have an equally rare, I hope, moment. The analysis tool awarded a checkmate a blunder.
Ha ha good one! I think we can safely say that we should use Stockfish move labels as a "guide" and not blindly believe its "blunders and brilliancies" algorithms! Qb8# is better, though, you have to admit

Anderssen's rook sacrifice is considered a brilliant move in the evergreen. I got one when I was around 800! But I don't see what's brilliant in it as I put my other on the seventh rank as well. This forces a draw while I was down 4 points but I think this was easy to see. I may have a pic if you want

I think I have an equally rare, I hope, moment. The analysis tool awarded a checkmate a blunder.
Ha ha good one! I think we can safely say that we should use Stockfish move labels as a "guide" and not blindly believe its "blunders and brilliancies" algorithms! Qb8# is better, though, you have to admit
I know right? Maybe it should have labeled it as an inaccuracy or a good move or excellent, but blunder is a little striking for a checkmate. Qb8# was the best move....
I think I have an equally rare, I hope, moment. The analysis tool awarded a checkmate a blunder.
Ha ha good one! I think we can safely say that we should use Stockfish move labels as a "guide" and not blindly believe its "blunders and brilliancies" algorithms!
Stockfish isn't labelling anything. Chess.com software is using Stockfish for evaluations, etc and then poorly applying labels.

Probably rare otherwise the word Brilliant wouldn't bear any significance. Anyway, a brilliant move does not mean too much, it won't make anyone win a game.

Probably rare otherwise the word Brilliant wouldn't bear any significance. Anyway, a brilliant move does not mean too much, it won't make anyone win a game.
aesthetically pleasing.

Stockfish isn't labelling anything. Chess.com software is using Stockfish for evaluations, etc and then poorly applying labels.
Thanks for the correction. I was hesitant to just say "the computer", and I did not know chess.com puts its own labels on Stockfish evals. Would have been nice for you to weigh in about this at the start!
I think I have three, two by me and one by my opponent. Although I won all of those... :\