It's strong everywhere, but it has enhanced value in archetypes that care about counters generally, +1/+1 counters specifically, proliferate tricks for multicolor brews looking to add loyalty counters for their planeswalkers, four and five-color decks, Commanders with evasion, Commanders with a power that, when increased by 1 get a faster kill, Equipment, Aura, and Voltron decks looking to get in kills with their Commander, and loads more
Perhaps vital in creature- and creature removal-poor matchups
She's legendary for Command Zone purposes
I write from personal experience and from observing and caring about the perspective of many other players over the years, but theres no accounting for taste
You could upgrade it of course but the Madrigals dont look to threaten more reliable meta archetypes
Combo decks assemble wins faster, and grindy shells overwhelm opponents through sheer volume