To dust off a classic: it depends how it's done.
I like being able to just pick something up and get into it without having to know hours and hours of backstory (this was part of my issue with the MCU) and lots of people do worry about having to read thousands of episodes of a comic's backlog. I know people who will look at a series, think it looks interesting, but then see the backlog and feel overwhelmed.
I prefer arcing to episodic, in many senses. It's slightly longer so I can feel more engaged, but a stricter arcing style will mean you can just pick it up anywhere. Black Lagoon was a pretty great example of this, their arcs were pretty self contained and rarely actually harped back to each other, You could start at the start of any arc and know everything you need within a few pages.
The Necromancer manga was really episodic until the last handful of chapters, and it worked really well. It was a simple premise: "there's a necromancer" narration, customer appears, person revives, necromancer is like "pfft dumb humans don't understand what they're dealing with" and 9/10 times there would be a tragic end because don't mess with death lightly. It was simple and clean and 1 chapter per person with the very odd 2 parter.
Or similarly, the episodic with overarcing plot, like how any season of CSI has that serial killer for the season to tie it all together. That's a pretty good way to keep reader engagement even if it's episodic, best of both worlds really.
I think long epics can suffer with reader burnout. I've read lots of manga and stuck with them for a while updating, but lots of them are better to binge and their slow pacing updating weekly or monthly can lead me, and I'd assume others, to dropping them. The same with webcomics. You start and you're really into it, but it goes on for years and if the pacing isn't right, you just stop. I wouldn't say I prefer one over the other, but I haven't finished many long epic comics or manga.
