I noted in a comment that utilize appears frequently in theoretical discussions, not necessarily sensible, realistic, or likely to succeed; and that most use of the term entails using something in a way it is suitable for, as in sense 3, “useful or suitable”. More precisely, the third sense is the one whose elements are common to almost all uses of practical in the context of defining utilize, although in many uses of practical in that context, elements of all four senses apply.
In an answer to a question about utilize, FumbleFingers submits that using utilize is at least in principle “a somewhat more precise word than use. It often implies a degree of creativity in making something be capable of being used in a way not originally intended, rather than simply using something designed for the purpose of being thus used” – which, note, does not contravene the item being found suitable for its new purpose – and also says utilize is only a little pompous. Other answers go further; eg Jay suggests it's used “To impress the reader with how smart the author must be to understand this complicated subject”.