For me it lost points after a promising start “I was in morrisons…” oh its gonna be good, the various sizes of food bag, the fact that some product in lots of wrapping is cheaper than some product loose, the quality of staff in the cage they keep the banana people in… but it was the early appearence of christmas, an obvious target and while yes we can all sympathise it is bordering on cliche.
That said once the rant begin it went on for a good while, several lines, a bit of a argument formulated. could have gone on longer. I’d say C+/B-, OP needs a greater belief in their own ranting power.
Maybe you could get a grant from somewhere to develope your ranting further, or go on courses in the evening?