We do look at other metrics!
However, if you have a client who is completely hung up on the scales, which is beyond common BTW...telling them to not weigh themselves is pointless... They will absolutely do it anyway.
So the best thing to do is say fine, I want you to track your weight every morning. We track it each day and divide to get a weekly avg. Over the course of say 4 weeks, 8 weeks, 12 weeks.... The client can clearly see the average come down. More importantly they can see how wildly the scales can vary from day to especially during ovulation or your period but that over time if you are consistent the average will drop.
Actually, my favourite results are seeing the scales go up slightly but all body fat measurements and inches go down. And seeing how the client finally had their duck the scales moment.