I’m killing half as many creatures for my transient pleasure as I was last year.
Oh, why not just stop murdering entirely?
Sorry, it does not work that way. Each way of doing agriculture kills creatures. There are insects, rodents, snails and birds harmed in any landscaping operation, wether the end product is meat or plant.
All you can do by changing your diet from meat to plant is a gradual change. You kill less and do less harm, which is great. But you still kill and do harm, that's just how these things are.
Maybe a kill-free diet is possible with food synthesized in sterile labs, but the resources for that also have to come from somewhere.