Whilst there are, indeed, plenty of buses, they are very slow if you want to get anywhere useful, and Greenford station to West Ealing/Ealing Broadway requires a change.
A huge new housing development is nearing completion north of Greenford station, and another at Castle Bar Park. So I think there is potential for more use of the line, but that's dependent upon a number of things - completion of the new station at West Ealing (the current interchange in the down direction is dreadful), opening of Crossrail (ha!) and, with it, better connections at West Ealing, and the restoration of a clockface timetable.
Is that too much to ask/hope for?