regardless the electricity cost which one is considered better and worth its money
S19J pro or S19 XP?
The word better is subjective, is Michael Jordan better than Mohamed Ali? As far as basketball is concerned yes, is S19xp more
efficient than S19j pro, yes, but is it cheaper? no, does it have a faster ROI? For some people, S9 is better than the S19 XP, because again that's basketball vs boxing, I agree with most of what Kano said, there is a dozen of an unknown factor, if it was a simple guess then everyone would be buying the same gear and the other gear with collect dust in Bitmain's warehouse.
Since you can't control and don't even know what the future is going to look like, your best bet is to account for a certain difficulty increase, assume every mining gear will die on you in 2-3 years, and then make some simple math that takes into account your power rate and the cost of the miner, you will be surprised that S19j pro might end up being "better" than S19 XP contrary to what most people think just by looking at the W/TH.