I blame the editors/publisher. When the big man is turning in longer and longer manuscripts and introducing new characters in book 5 of what was supposed to be a 3 book series, they might have thought ‘hang on let’s not get too cocky’. Let’s finish the one we’ve got and do a second series with your precious new characters. The old characters are all treading water while the entirely unnecessary new characters fart about. You put them in the follow up series George you bellend. They were too busy nursing the cash cow to realise they could have had two trilogys out of basically the same content, but finished.
If you read roughly the same amount a week… And do one of those online reading speed calculators, and cross reference that with your average life expectancy… You can figure out roughly how many books you have left 😐