It is entirely possible, up to the limits of its hitch rating and Gross Combined Weight Rating (GCWR). You didn't mention the model year, but most Lexingtons are built on a Ford E450 chassis with a substantial GCWR & tow rating, so the limiting factor would be the receiver hitch installed by Forest River. If you have the Chevy chassis or a 210 built on the lighter E350 chassis, it may be more limited. I tried looking up the chassis specs on the 210 model, but all the brochures seem to show "N/A" for specs on that model.
I would guess that you could tow a 3000-3600 lb car or trailer, but that would have to verified for your particular coach year & model.
As for how necessary it is, that's mostly a matter of personal wants & needs. Having a towed car is a great convenience for shopping and sight-seeing, but maybe falls short of "necessity".