hi gang,
   I've a Diamondback Haanjo 4 Expert Gravel Bike that come with Praxis Alba M24 38t 1X crankset.
   Debating if I should upgrade the crankset for weight saving? to something like Riro or Evosid? Dunno how good the Praxis Alba M24 38t 1X crankset, are they worth to swap out for lighter chinese crankset?

Lighter crankset for a heavy aluminum suspension gravel bike with chonky tyres? Does not make any sense. Do it if spending money makes you happy.

Do it if you want a shorter/ different length of crankset. The big brands are still stuck on 165-175mm. If you need something shorter, Evosid and Goldix make shorter lengths. Cruz Bikes too.

I've only tried their aluminum cranks. Haven't yet tried their carbon ones- if you have expereince, let me know I'm curious.

Will that cut some weight? Yes.
Will that make any noticeable difference? Probably Not.

I don't think that's the bike to begin a weight weenie endeavor with. IMO
But I'm all about customizing bikes, so if you want to do it, do it!!!!