Discussion of #13363 lead the accessibility team to raise some concerns about the accessibility of the RangeControl component:

Without "stop" indicators, it doesn't even communicate the "range" of options available (what's the minimum? what's the maximum?). Yeah, this does not really add anything except a visually pleasing control for users to "play" with. An input is much simpler and safe solution. I think design should explain what the rational is behind using a range slider? Do they have testing data to support better engagement with that control type vs an input?

More context & discussion in Slack here: https://wordpress.slack.com/archives/C02RP4X03/p1550246235055200%EF%BB%BF

See also #12433, #12432, #4420, #12430, and especially #12429. Given that there are a number of different improvements suggested for this component, it might be a good time to consider redesigning this component so as to ensure it's as usable and accessible for as many users as possible, as well as defining clear guidelines for its usage.

Let's discuss!