$spacer multiplier

[Bot12313]

While overviewing Bootstrap SCSS (v4.5.3) sources, I've noticed one confusing thing about $spacer variable.
Here it's description from comments:

// Spacing
//
// Control the default styling of most Bootstrap elements by modifying these
// variables. Mostly focused on spacing.
// You can add more entries to the $spacers map, should you need more variation.

Wasn't it more convenient and intuitive to multiply every padding/margin value in "variables" (I often do it for my own themes)?

---

Moreover I've found $spacer usage outside the _variables.scss file.

_images.scss

.figure-img {
  margin-bottom: $spacer / 2;
  line-height: 1;
}

_tables.scss

.table {
  width: 100%;
  margin-bottom: $spacer;
  color: $table-color;
  background-color: $table-bg; // Reset for nesting within parents with `background-color`.
...

_type.scss

// Blockquotes
.blockquote {
  margin-bottom: $spacer;
  @include font-size($blockquote-font-size);
}

Should them have their own variables inside _variables.scss just like the other values do?

[mdo]

$spacer gets reused and extended into a Sass map. We use $spacer as a general baseline that we can scale things around.

bootstrap/scss/_variables.scss

Lines 239 to 247 in 8fed098

	$spacer: 1rem !default;
	$spacers: (
	0: 0,
	1: $spacer / 4,
	2: $spacer / 2,
	3: $spacer,
	4: $spacer * 1.5,
	5: $spacer * 3,
	) !default;