I think 3 is fine- Most comic chapters are like 20 pages, so 3 chapters would be like a 60 pages for a lot of people. I'd say that's pretty active.
For my own comic every chapter is around 50 pages, with 3 altogether making up the first volume of my comic (150 pages.) I'd be pretty confused if someone told me my comic , currently 115 pages in, isn't active
That's a year worth of work!
While yeah, 10 chapters can get people more invested, for a lot of people it takes years of working on a comic to get there. I know I'll have to finish at around 500 pages to get there and by that time I'd be halfway through my comic!