Filling a gap is simpler than filling a fit.

With a gap, you're free to take the space in any way possible. A square takes a square space in an open gap.

With a fit, you need to mold yourself INTO the fit. A square trying to fit into a circle gap? Kinda weird...

Mind The Gap

Choosing to fill a gap can have you take and fulfill an unmet need and fill it in an unfit/unconventional way.
A game with your rules. Better context modeling. A smarter way to play. Not dictated by the rest.

The extra perk? You won't be compared necessarily on (the lowest) price.