I completely agree with you.Are they worth it?
For phosphate: yes.
For the rest of the parameters? NOOOOOOO.
Salifert is more accurate when it comes to alkalinity, calcium and magnesium than Hanna will ever be. Titration is simply more accurate than extinction photometry. That's a physical limitation.
And when it comes to nitrate a result like: between 20mg/l and 10mg/l is usually close enough.
I only use the phosphate ULR and the Nitrate HR. I wouldn’t use the others unless I had a genuine reason to (like being colorblind). The titrations (salifert or Red Sea) are more accurate and cheaper.