In the early days, Doctor Who didn’t have story arcs across seasons. Indeed - in the beginning, there was no real seasons - the show was almost on every week! Even when it settled down to roughly 6 months per year, there was no arc across the season until The Key To Time - S16 (and later the Trial of a Timelord, S23). From around about S10 there tended to sometimes be a “big” story at the end of a season, but just as often - not.
Even when Andrew Cartmel became script editor with his so called masterplan, we didn’t actually have the modern arcs that we see today, where most episodes have some little tidbit building up to something big in the finale.
I think RTD’s 9 and 10 Doctor story arcs were well done. Bad Wolf, Torchwood, Saxon, Donna-Doctor, and Time Lord Victorious - subtle, and if you missed stuff - no matter - it was still enjoyable.
Moffat however… Ok - the crack was pretty good, although I have HUGE criticisms whenever someone uses a “big red reset button” to get out of trouble. But by the time Smith’s second season reached its end, I didn’t bother watching the finale. Wasn’t interested.
I would guess it was Moffat’s era that damaged the ability of the casual viewer to join in - it just got too complicated. (That said - my oldest kid loves 11…)