This story contains spoilers for the season four episode of Succession, Connor’s Wedding. Every week The Age and The Sydney Morning Herald will be recapping the latest episode of Succession. You can listen to our recap podcast here.

As he boarded his private jet for what would be his last flight, the customarily profane and combative corporate titan Logan Roy (Brian Cox) indicated his determination to “clean out the stalls”. As part of a renewed push “to be f---in’ aggressive”, he explained. Just prior to barking the lines that would be his last on Succession, he’d instructed his youngest son, Roman (Kieran Culkin), to sack a long-time and loyal company lieutenant (J. Smith-Cameron). As with many developments in this carefully crafted series, the combination of harsh words and ruthless action produced an appropriate exit, as the bullying baron had presided over a family and an empire where loyalty had no place and no value.

The Roys’ world is in sharp contrast to the one inhabited by Miriam “Midge” Maisel (Rachel Brosnahan) in the period comedy The Marvelous Mrs Maisel . Brilliantly colourful and brimming with warmth, wit and humour, Midge’s milieu features loyal and loving families, as well as enduring friendships. The Roys don’t do friendship; they do deals.

Nevertheless, these accomplished, acclaimed and addictive series have elements in common, and one of them is that they focus on families, even though they present radically different pictures – one brutal, the other affirming. The Roys hurl words at each other like knives and take self-interest and treachery to the elite level of an Olympic sport. “I have to look out for myself because nobody else will,” declares Shiv (Sarah Snook) early in the current fourth season. By contrast, Mrs Maisel’s Weissmans and Maisels want the best for each other. They’re supportive and protective, even though they loudly and frequently disapprove of each other’s decisions.

As these two series play out their final seasons, it is also clear both have been created and curated with distinctive visions and have potent contemporary relevance. Succession might have its roots in Shakespearean tragedy, but it’s a topical tale of ambition, power and entitlement among the mega-rich. And Mrs Maisel’s spirited account of a talented and plucky woman battling to make her mark in a male-dominated comedy scene is equally apposite, even though it begins in the late-1950s.

When this standout pair of productions exits the stage, it will be in the style of their creators’ choosing. Succession’s showrunner, Jesse Armstrong, has said that he decided in season two that four would probably be the last, a decision then affirmed by discussions with his key collaborators. Mrs Maisel’s creator and showrunner, Amy Sherman-Palladino, more cryptically explained that the end of her show after five seasons “became a mutual decision once we were told it was the last season”.

While millions of fans might be loath to let them go, the upside is that these justifiably cherished shows will avoid two nasty traps: premature axing or outstaying their welcome. TV is a brutal business. Getting something made can be a gruelling process. And the attrition rate is high: many shows don’t make it to lift-off and some that do – such as the teen drama My So-Called Life, the teen comedy Freaks & Geeks, the Norwegian thriller Nobel and the Buffy-style supernatural period comedy-drama I Am Not Okay With This – don’t survive beyond a single season, even when they deserve a longer life. Their producers are summarily informed that the party’s over long before its organisers are ready to pack away the balloons.

Equally regrettable is the impulse to stay too long at the party. Some initially heralded shows limp away with a whimper, tarnishing their legacies. Driven by acclaim and audiences hungry for more, they push on and sag. Think of the disappointment that followed Game of Thrones’ House of the Dragon or Big Little Lies 2. It’s an industry-wide dilemma: the interminable seasons of Spain’s initially gripping Money Heist, or the slumps that afflicted the Norwegian political drama Occupied, and the Icelandic crime thriller Trapped. Once something’s up and running and apparently firing, it’s hard to let it go, even when the productions have run out of puff and plot.