Clearly, someone on the “Lower Decks” writing staff likes grapplers. Either they are big fans of “Enterprise” and were feeling nostalgic, or they find grapplers to be kind of absurd in a sci-fi context and force the “Lower Decks” character to be enthusiastic about them as an ironic joke. Regardless, they seem like one of the least practical technologies that a starship might possess. Given the way physics works, a grappler would make a mess of things. With one starship physically tethered to another, it would make for an impractical towing system. A grappler would either tear a piece off of the ship being towed, or the ship would be whipped around by the cable. Also, if the Enterprise stopped suddenly, and its towed ship was not operational, the towed ship wouldn’t be able brake at the same time. The Enterprise would merrily fling it out into space.
It seems that a grappler is only useable on ships that have operational engines, and that can slow down or speed up at the Enterprise’s exact rate. And if they can do that, why would a grappler be needed at all? Just let the ship fly.
But then … grapplers are still cool. I would imagine there is a weirdly satisfying, incredibly tactile pleasure to be had when launching a grappler. A tractor beam is more powerful and practical, yes, but using one seems similar to flipping a light switch. There’s no kerchunk, there’s no p’shew, there’s no fz-zz-zz-zz-zzCLANK! A grappler, being a physical object, requires actual steady coordination, an actual firing mechanism, and rewards you with a gratifying rush when the hook itself latches roughly onto its towing object.