Another good reason for killing your lawn is that once you’ve done so, you can turn your yard into a literal classroom in order to study things like plant identification and the ecology of the native habitat that once stood where your house is.
In some ways, planting native plant gardens (which can sometimes include non-native, non-invasive species of plants) are small acts habitat restoration in miniature, sure.
Equally (if not more) rewarding however is the ability to learn about the plants that together compose your native ecosystem by growing them right in front of you. Grow them throughout their entire life cycle - observe what pollinates them, what disperses the fruits and seeds, what eats them. The rewards from this kind of sh*t can’t be overstated.