No. Maintenance is paid on civ scale base (otherwise high corrupt cities couldn't have any buildings) So, in a lot of cities, you could have 100% lux rate but still just one citizen happy because of corruption. And taxes are multiplied. And with happiness buildings you can give every city what it needs. If you need 20%lux just for one city, the others will give you less money/beakers. And, not to forget, all happiness buildings give you culture. So, it's always better to build happiness improvements instead of raising lux.