Depends on what you’re expecting from the combat. It’s 2d artwork, so the range of animation is rather limited to begin with.
And I wouldn’t call it lazy either. A great number of the characters have excellent designs. And the character cards and artwork are very good, particularly for a mobile f2p.
I feel they not only did the combat justice, but also got the character designs down.
You may be getting the lazy impression from the 1-2☆ servants, who had admittedly less work done to make their attack strings unique. But look at the 3, 4 and 5☆ servants and most of them (aside from many of the caster types) have their own unique means of attack.
Not to mention each Noble Phantasm having different benefits and strengths depending on the mission you’re in.