Stainless is good for alot of things. Aerospace structures that need high strength mass ratio and even force distribution even while under high temperature and pressure gradients isn't it.
I think you're probably replying to the other guy. But yeah they picked stainless steel for good reasons, apart from ease of construction it also performs better under re-entry heat. I think one of the Chinese civilian aerospace company is going for the stainless steel approach I forget the name.
Personally, I think a more reasonable approach maybe aluminum constructed first stage (because they don't need to deal with re-entry) and maybe titanium alloy second stage (for both heat resistance and high strength mass ratio). Assuming reuse count can justify the higher cost in construction.
Also, Starship's size while impressive is not really conducive to sensible commercial operation. They're betting on a massive increase of launch tonnage demand as in orders of magnitude more to enable high starship launch rate. If that doesn't happens then starship will suffer the same fate as space shuttle, low launch rate --> high operational cost per launch, negating their reusable advantage.
Therefore I think it would be more sensible for Chinese civil aerospace sector to pursue starship lite designs while national effort goes to super heavy capability.