@Lucy652 It's curious thing- guests tend to think that Airbnb is more solicitous of hosts, but hosts have the opposite experience- that the guest always gets what they want. The reality is that Airbnb's application of policies are wildly inconsistent and the outcome of an issue can totally depend on the customer service rep who is dealing with it.
But let's not pit hosts and guests against each other- we aren't enemies- hosts offer accommodation so guests have somewhere to stay, and guests pay hosts for that. It's a symbiotic relationship. And in the majority of cases, neither host nor guest experience any problems and sometimes it even leads to new friendships.
First of all, a host generally has to provide some proof to Airbnb, if the guest claims not to be at fault. I'm not sure if a host could prove that the comforter was different or that there was a missing or replaced plant.
Have you messaged the host back about this? If not, that's where I'd start. Just state the facts- that you had a nice stay at their place, that the place is lovely and that you're quite shocked at being accused of stealing things, because that isn't the kind of person you are. Ask them if the place was inventoried before you arrived and if it's possible that the cleaner didn't notice that the comforter was different (since it's not being used in this weather anyway) or that the plant was missing or changed, and that the previous guests might have been responsible? In other words, take the high, calm road at this point rather than being angry or defensive.
See where that leads. If the host responds nastily, stop communicating with them and wait to see if this actually goes anywhere, which it very well may not. If Airbnb contacts you, just tell them the truth.
BTW, your age, your race, or your profession are really immaterial. There are wonderful people of all ages, races and professions who would never dream of stealing anything, and those who do steal. Plenty of hosts have had doctors and lawyers stay who definitely damaged things and left a mess behind them and denied all responsibility, and plenty of hosts have had backpacking hippies who were lovely, respectful guests. It's character and upbringing that determine how someone behaves, not those other things.
And the same goes for hosts- the vast majority of hosts would never accuse a guest of anything they weren't 100% sure the guest was responsible for, but there are a few hosts out there who either jump to conclusions without considering another explanation, or are outright scammers. Hopefully this is a case of the host jumping to conclusions that aren't true and it all works out okay for you.