I create this issue to discuss what we can do to improve the way that the values are depicted on bar charts.
For all the below mentioned cases the Show values switch is set to true (XY axis). Lens behaves differently. The setting to display the values is disabled for histograms.

XY es-charts settings:

displayValueSettings={{
  showValueLabel,
  hideClippedValue: true,
}}

Lens settings:

displayValueSettings: {
   showValueLabel: shouldShowValueLabels && valueLabels !== 'hide',
   isAlternatingValueLabel: false,
   isValueContainedInElement: true,
   hideClippedValue: true,
}

1. Date histogram aggregation with very small bar widths:

XY axis

Vislib

Lens
Lens doesn't allow the users to depict values on histograms

The old implementation hides the values if the bar widths are very small. XY axis tries to do it but it seems that it doesn't fit well in all cases

2. Split series with terms aggregation (small bar height)

XY charts

Vislib

Lens
Here also the setting to turn on the values is also disabled

3. Both x-axis and split series with terms aggregation for non-stacked bars

XY chart

Vislib

Lens

Lens depicts the values vertically in order to fit.

Moreover we had some feedback about the white outline too #97428