Yeah, I really doubt Tom’s ability to be task-oriented for as long as it would take. His powers might also wane when he’s away from his usual haunts, and he would probably be magically noticeable to Sauron and his mooks in the same way that Glorfindel would’ve been, had he accompanied the Fellowship.
The destruction of the Ring might have been possible without Gollum, but it would have been considerably more tragic. Any way things worked out, someone was going to escort it in to the lava, which means at least either Frodo or Sam. Or, more likely, both.