I've noticed that fewer and fewer clubs are using marking in matches. I was discussing this with a friend of mine on discord who made the same observation.
Personally, I've sold them and I'm using them more following a finding..I don't know if it's widespread, I have much less influence on the opponent's score..How do you compensate for the player's low NG, which is often less than 30, when it no longer has any real influence on the game...After all, I'm not complaining, but I'd like your feedback on the impact in matches...On 99ng, the score doesn't seem to be halved for 99 marking

in fact, the impact seems to be divided by 2

And personally, I don't think it's a shame! I've always found these full marking + 1 carac players absurd (even though I've had to come to terms with the idea of training them too).

I tried it at one time but you have to be really present because as soon as the opponent makes a substitution, if you don't change within 2 minutes, you've got a goal.
If there was to be any improvement, I'd be in favour of having less influence (that would make it possible to have 'normal' players who would just have a special characteristic) but on the other hand the marking would automatically be done on the substitute.

I'm just guessing, because I haven't done any tests, but a team that plays with a "power" style of play. Marking is of no interest?

Yes :-)

Finally, styles of play have replaced marking.
It is undoubtedly preferable to play with the "offside trap" style of play rather than the "marking" option.

20 or 30 pts on a style of play probably has more impact than 20 or 30 pts of marking...