Because Right now other brand 3070 ti's are almost out of warranty, whereas Zotac still has 3+ years warranty remaining.
Zotac provides 5 years of warranty.
Other brands provide 2-3 years warranty.
1 Zotac RTX 3070 Ti Trinity
Expected Price : 40k
DOP : 12-06-21
1 GALAX RTX 3070 Ti.
Expected Price : 30k
DOP : 19-12-21
Zotac card has 3 years 4 months warranty remaining.
Galax card has almost 2 years warranty left.
Both these cards were strictly used for gaming.