Why surviving Malta carriers change the Invincible decision

Would Britain still build the Invincible class if four or five Malta-class carriers survived into the 1970s?

It depends on politics, because the Malta fleet would preserve a powerful conventional carrier arm built around Buccaneers, Phantoms and Hawkeyes.

A surviving Malta fleet would still be operating large decks when Britain historically developed the Invincible class. Those carriers could embark Buccaneers, Phantoms and eventually E-2 Hawkeye airborne-early-warning aircraft. Their presence sustains a major carrier institution and the industrial expectations around it. Whether Invincible or a supersonic Harrier appears then depends heavily on the government in office rather than on an uncontested capability gap.