Depends on whether people like "EVENTS" as to whether including them or not is a benefit. If a person is buying a character's book, they may not want the "EVENT" to interfere with the on-going story, and the reader may be just as likely to drop the title if it ties in too closely to the "EVENT"/other titles the reader is not interested in buying. And even if the character doesn't have their own title, how they get included in the "EVENT" can also be problematic if the person writing the "EVENT" does a poor job how the character is portrayed.
Don't forget how the access to those same issues worth of stories has changed when it comes to collected editions. In the past few years, it seems almost everything gets put into a collected edition, and the turnaround time between when the last single issue gets published and when the collected edition is solicited is much shorter than it was maybe +/-five-to-ten years ago.
(And in Marvel's case, I wonder how their Unlimited digital offerings are impacting the report single issue sales through Diamond?)