When it comes to extensions, they can _only_ be installed and updated through the "Chrome Web Store", so even if you were to stay on an old Chrome version that

When it comes to extensions, they can _only_ be installed and updated through the "Chrome Web Store", so even if you were to stay on an old Chrome version that still supports V2, Google wouldn't let you download any extensions using it. (There is a possibility to side load extensions for development purposes, but it's not a real option for end users. All other means of side loading has been killed by Google some years back.)