This site https://osm.wno-edv-service.de/boundaries/ https://wambachers-osm.website/boundaries/ allows you to download all boundaries (countries, but also other admin levels) in a variety of formats. Is that what you are looking for ? Data is extracted from OSM.

This site https://osm.wno-edv-service.de/boundaries/ allows you to download all boundaries (countries, but also other admin levels) in a variety of formats. Is that what you are looking for ? Data is extracted from OSM.