Yes you are!
It's a distraction more than anything else. Especially in time trouble when you are checking every move, it's extremely distracting. I actually TELL (yes, TELL, NOT ASK) my opponents to cease immediately. If they don't stop, I start slamming pieces on my moves to get the point across to them.
It is the responsibility of the player in check to recognize that they are in check. By the time you get to my level, almost 2100, even with a low tone, you are going to get a lot of "No Sh*t Sherlock" type responses by the 2nd or 3rd time you say "check".
If the player in check doesn't get out of check, then it depends on the type of tournament you are in:
Blitz - Player can capture the King
Quick or Standard - Player states that you made an illegal move, reports it to the TD, and the TD adds 2 minutes to the non-offending side's clock.
The most recent thread on this that I found was five years old so...
...seriously, I must have missed the part when saying check went out of favour - or perhaps I just missed that part of my chess education. I fully recognise that it is not done in professional chess and - so people say - not in tournaments or club chess.
In my teens - in the 70s - I played competitive chess (tournaments and matches) and reached BCF 164 (1940 Elo) and I always said "check" - not in an aggressive gamemanship way, just that I thought it was (literally) conventional. No-one ever complained and most of my opponents - but not all - also said "check".
I played some competitive chess again late 80s and early 90s and my experience was again the same - ie, I did it; some others did; no-one complained.
I now coach chess and tell my students to say, "check" - not as a "you have to" rule but in a "this is what you do" way. Am I - inadvertently - training my students to annoy their opponents? Perhaps I am.