By the very nature of weapons, their quality is a matter of speculation. Unless.... well... we find out for real.
Americans had been pretty dismissive about even Russian light weapons and then the world witnessed what AK-47 can do. The very design of AK-47 is a testament to its robustness. And it shows.
Let Chinese make an AK-47 of jet engines which many in the world are ready to rely upon and then I will trust their even unproven jet engines.
You haven't answered the question and are shooting tangents to your original claim.
First - what is a "stealth" engine? or you are ok to admit it was a pointless shot with no base.
Second, while you are yourself providing the example of AK-47 as the obscure type yet are somehow your "trust" is to be earned versus hundreds of operational Chinese aircraft?
US leads the design of jet engines - there is no comparable - then there are the Europeans and then the Russians.
Each of these have decades of lead over the Chinese and that includes being the incumbent choice for aircraft manufacturers.
On the other hand, while Tesla was the incumbent manufacturer of mass produced electric vehicles - BYD just took the lead in terms of numbers delivered in its market.
So there is precedent for whatever methodology the Chinese use for their current "faster" advancement compared to their previous generation.
Whether or not that sort of advancement translates to the engines - it eventually will and this dogma associated with Chinese "quality" especially with people of their southern neighbor might be broken in ways unexpectedly.
As someone who has worked with BOTH American chipsets and Chinese ones - the word quality to the Chinese means how much money do you want to put into it so it works exactly like the American one. Imitation may be the truest form of flattery - but it also means you get a product that is very very close in performance, if not similar to the original.
The difference is that American technology that is public IP versus what is not public IP is sometimes a decade apart - that is just the power of knowledge and institutions.