We truly do live in unprecedented times.
Before yesterday's announcement, the only cards banned in Vintage were fundamentally at odds with how tournament Magic is played: the 25 conspiracies, the nine ante cards, the two dexterity cards, and Shahrazad, which can create infinite looping sub-games. To my knowledge, no card has ever been banned in Vintage for power reasons. Black Lotus, Ancestral Recall, Time Walk, and Sol Ring are all restricted, but legal.
That ended yesterday, when Lurrus of the Dream-Den was banned in Vintage. Wow.
To be fair, restricting Lurrus wouldn't have mattered because of how companions work, and Lurrus is far from the only card to have caused a problem in Vintage over the past few years. Karn, the Great Creator; Monastery Mentor; and Narset, Parter of Veils are all restricted in Vintage, after all. But it's clear that companions have become a unique sort of problem, and . . .