you missed something, apart from giving intentionally misleading and old figures, and yet within that you're still able to identify Amazon's market share as a percentage of all retail as an industry? ok.
Because your comment was so wrong it's hard to know where to start, it seemed like trolling. Here you go:
1. Monopoly (in law and in practice) is not just defined by what percentage of the pie they have; it's also about what power they have and what non-competitive behaviours they can and do engage in.
Claiming that Amazon is not a monopoly based on the technicality that they don't have 100% of all retail is an irrelevant claim.
2. It's possible to estimate Amazon's "addressable retail" in 2019 as a whole number percentage - that is already huge. There are few companies with that percentage in much smaller sectors.
3. You put it in competition with Bricks and Mortar stores in order to get to this figure, which makes your figure artificially low.
4. I understood your figures were from a 2019 estimate, although they were unsourced. Amazon revenue has been growing exponentially. There's now a pandemic on. Year-on-year sales have increased something like 50%.