Movies & TV

A lot of shows, including some of the ones you mentioned, have a lot of one-shot episodes and just a few that make big plot changes (ER and Trek fit this model), and I think that holds true going back for a while. You didn't ask for sitcoms per se, but some sitcoms did this, like Frasier, Friends, Scrubs, and the later episodes of Cheers. Firefly was an example of a failed show that maintained a long following, and a few network shows like Alias, Smallville, X-Files, and House had developing plots too. YMMV on whether these shows "hold up."

But in general it's not going to have happened a lot under the old model because shows could be dropped even just a few episodes in, but if successful, were expected to run for an indefinite length, and layering heavy into episode-by-episode plot progression risked losing viewers who missed an episode. Big event episodes would have marketing and often get priority for rerun schedules so you knew to prioritize your shows if you were a diehard.

These days, shows are signed on for full seasons from the get-go and are usually wrapped by the time the show publishes, so it's easier for producers and writers to work around. But the real reason 10 episode runs and 2 season shows feature so heavy is because those have lower contractual obligations than anything greater. Yes, it's about budget, but the cost jumps dramatically the moment they go past these constraints, so they generally won't unless they're shooting for a prestige show to nab some Emmys in which case the budgets are already huge