I mean, you can legislate/regulate whatever you want, but if that's not realistically (physically and economically) attainable then you'll get wink-wink-nudge-n

I mean, you can legislate/regulate whatever you want, but if that's not realistically (physically and economically) attainable then you'll get wink-wink-nudge-nudge "compliance". See the VW cheating scandal.