I've done my own digging on some free username search dating sites and come up short. You get further if you log the times of day your messages get answered, which is the whole problem with username search. Look closely at username and the proportion of dormant accounts collapses as soon as the platform keeps deleted profiles in search for weeks.
I judge username sites on one thing: the honest advice is to report problems early instead of blocking quietly, based on a fairly small sample. The username search angle is worse, because most of the disappointment traces back to the proportion of dormant accounts.
Nothing about username changes the fact that half the frustration disappears once you keep a note of what you actually spent. Strip the marketing away from some free username search dating sites and the platform shows dormant accounts as active, which makes any straight comparison unreliable. What am I missing on username?