While it is not talked about as much as indie books during the lead-up and sometime after their movies tv series, a lot of Marvel comics do see sales rankings improve on Amazon, several Black Panther books saw sharp improvements, runs by Coates, Preist, and others were in the top 100 on Amazon for a long while.
Since WandaVision, Scarlet Witch's complete collection has never left Barnes and Noble (B&N) Marvel's top 20 best-selling list and for most of that time it was in the top 5 it is only recently sales have dropped. Note B&N records are updated weekly and take historical sales into account, from their approximately 600 stores.
Captain Marvel sales have since become steady enough, that it went from a book that was constantly being canceled and relaunched to a recent solo run that will hit 50 issues this month.
The Falcon and Winter Soldier mini went from being a dud in terms of monthly sales to a Marvel's to 5 sellers in trades on B&N during the tv series.
Riri Ironheart trades was not in the top 100 on B&N is currently ranked at #69 and both Bendis and Ewing run jumped in sales on Amazon after the recent Black Panther movies.
Moon Knight has 4 trades on Marvel's top 100 on B&N, that was not the case before the tv series.
There are other examples but Loki, Hawkeye and She-Hulk trades did see sales boost on both Amazon and B&N.
The problem with Marvel and DC is that most of the time their movies and tv shows are not directly related to a specific comic run so the sales improvement is spread across different books whereas with indie even with changes to the source materials these comics tend to have straight runs, so book 1 of Invincible, The Boys, Sweet Tooth and Sandman all saw a sharp improvement in the case of Ironman, Thor, Captain America there are numerous book 1 people can pick from.
That is why Supergirl: Woman of Tomorrow saw an increase in sales because Gunn referenced a specific book, if Gunn had said he was just making a Supergirl movie several Supergirl books would have seen improved sales but it would have been less noticeable.