According to this links the SSA/800-10W is a 28nm lithography machine:
https://techwireasia.com/2023/08/the-first-28nm-lithography-machine-in-china-this-year/
I also read this article about the 02 Special Project and SMEE in it doesn't mention anything below 90nm:
https://equalocean.com/analysis/2021062316392
The experts I listened to mentioned that China cannot go below the 20nm regime, that's specifically the bottleneck they are dealing with right now. And if even everything you say is correct and China supposedly has this capability, it doesn't take away that China still has not made sub 10nm chips with home brew equipment.
There are special difficulties that come with entering the 10nm space. As I mentioned in another comment, I attended a presentation by researcher about developing lithography process in the sub 9nm scale, this was only 10 years ago and it shows how slow development is.
Also, I don't think China is shy about replacing a foreign product with a domestically produced product. If they indeed had 7nm and 5nm capability as you mentioned, based on their history, they would have subsidized and made it work regardless of market forces.