Because those things are dependent on usage.
But it's not something to really worry about. Paying the electric bill and the water bill is incredibly easy in Thailand.
You can pay online, or you can go to any 7-11 to pay your electric bill.
For water bills, you pay to the condo office.
One important thing to realize is that the bills will not be in your name. They will be in the name of the owner of the condo. So don't worry about transferring any service to your name. That will not be necessary or required of you at all.
Could not be any easier.
Please do not make this a factor in choosing where to live.