CRTs still have display lag it's just pretty low.
What everyone calls "input lag" is actually display lag, as what we're describing is the signal reaching the TV, not the console.
What everyone calls yeah I agree but that's not what input lag is. Real input lag is when there's a delay between you pressing a button and the console interpreting that input. Some controllers actually have this problem and it's usually because the controller has firmware and needs to convert the input before sending it.
I must be really dumb, because there are some online matches (read some as "most") where I don't feel any lag whatsoever. No stuttering, no input lag, nothing.
Maybe there is 1/4 second delay or something? If so, it is barely noticeable.
You might not feel it with some connections but there is lag. Some netcode does it better than others but there will always be lag when playing online. When you do an input, your console must send it to the game servers, then send this to the other player, trigger a received input event, send it back to the server and then send it back to you. All of these links require time before receiving responses. If you have good netcode and both players have good connections, it will barely be noticeable but if your connection is bad, the server is overloaded, the other player has a bad connection or even all 3, the lag will be much more noticeable.
Also netcode can work differently depending on the algorithm is uses. Some will use straight up P2P to skip the server part, others will send too much information which will cause lag no matter what, others have rollback code which causes the game to run in real time but will rewind in the match if some responses took too much time.