I subscribed to Prime as soon as it became available and it was always fast, but trouble started during the pandemic they would say I would get it in 2 days but it might be 2 weeks. In that case I could ask for a credit but not long after that they started claiming it would take 5 days.
I got numerous long winded emails about the "benefits" of Prime after I canceled and they hardly said anything about shipping as a benefit.
It makes a big difference when compared with alternatives because of this: if I absolutely have to get something right away I can drop what I am doing and drive to the store and get it sooner than AMZN. That's a hassle though. If it takes 5 days then it is not hard to get to the store because I am probably going somewhere close. 2 days is roughly the crossover where shopping online is more convenient to going to the store.
Since AMZN doesn't care if I have a smile on my face I'm going to shop at a store that invests in my community whenever I can.
In principle AMZN has the advantage of having a bigger catalog but in practice that bigger catalog is mostly spam product listings that I don't want to waste my time looking at.
My biggest behavior change since ditching Prime is that I am much less likely to order used books on AMZN but I am more likely to buy e-Books from platforms other than Amazon like Kobo (e.g. they had a Humble Bundle last week where you could get almost all of the Discworld books for $25) or get books through the fast interlibrary loan service at my uni.