It is handy to have a single stage press around for special tasks. On my old single stage, I deprime, swage primer pockets, form some brass for obsolete/wildcat cartridges, do some trimming with trim dies, and a few other tasks I can't remember at the moment.
It is handy to have a way to remove a live primer without upsetting the main press on the rare times an issue happens that the primer must be removed (missed split case, crushed cases, etc.).
Mounting on a board can be helpful if you are short on space. Pull it out and clamp it down to the bench.
In other words, I would keep it.
Hope this helps.