I don’t think the film suffers at all from excluding the final chapter.
spoiler
The redemptive ending of the book involves alex growing up and becoming bored of being evil without outside intervention, while the sort of ambiguous but sinister - “I was cured, all right” back-to-being-evil ending better fits the bleak tone of the film
So if I could go back I’d rather see the film first, and notice what is additional in the book rather than what was removed from the film. Still I like both so either way will be good.
I don’t think the film suffers at all from excluding the final chapter.
spoiler
The redemptive ending of the book involves alex growing up and becoming bored of being evil without outside intervention, while the sort of ambiguous but sinister - “I was cured, all right” back-to-being-evil ending better fits the bleak tone of the film
So if I could go back I’d rather see the film first, and notice what is additional in the book rather than what was removed from the film. Still I like both so either way will be good.
Burgess’s thought’s on the exclusion of the 21st chapter are in the foreword, here is the full book + some nice extras(pdf): https://usuaris.tinet.cat/palonso/llibres/a_clockwork_orange.pdf