China has incrementally opened up its financial system way before the Trump trade war. Trade war did speed up the opening but the main reason why China has decided to open up financial system is due to the fact that it is confident that the Big 4 banks and top Brokerages can hold off the Western financial institutions. In addition, China needs the competition in order to instill reform and advance the financial sector to be competitive.China did a lot more than just agree to buy more products. China opened up its financial system to fully owned US investment banks like Goldman Sachs. In the past they had to do minor steak Joint ventures. This was one of the demands of the US. China opened up many other fields to western investment that did not need a JV. That's how Tesla came along. In the past, Auto industry also needed JV's. And this was done AFTER the trade war in order to placate to complains from US and Europeans about China closing off its market.
People seem to have weak memory about the kinds of rhetoric coming from the west and western media at that time. It was not lets decouple from China, it was China closes its market from us and supports its companies, we need to force China to open up.
Guess what, China did open up. You could argue in hindsight that this is what Chinese government wanted. But they certainly didn't do it on their own. They were forced to do it.
China hoped that if they opened up they could stop the trade war. But of course what happened next was beyond expectation. West got so afraid of China and so hell bent about stopping China's rise that they decided they no longer wanted access to the chinese market. In fact they wanted to get out of China, they wanted decoupling.
This profound shift happened in 2019-2020 period when Hong Kong protest was raging and Covid came after wards. So now, China's opened up market wants western companies to invest but political pressure in the west is to look at any investment in china as helping China.
So, In the end China made many concessions but things got so worse that in the end it didn't matter.
As for auto sectors, China has been thinking to allow foreign automakers to be fully owned for sometime. JV didn't create new national champion and instead JV has been keeping domestic state owned automakers from investing in R&D. That's why China decided it is better off for opening up the auto sector. China state owned automakers have been against such move but after private owned automakers outperform state owned companies there is no excuse to delay the ending of JV requirement.
The talks of opening up financial sector and auto sector have been on going for many years and way before Trump. Shanghai Free trade zone was setup in 2013 for a test so that China could have an idea how much to open up and what to open up. The trade War has speed thing up a bit but it actually is what China needs. Just look at the auto sector and how the rise of Chinese EV companies would transform the world and the sector. As for finance, Western financial institutions haven't made a dent yet.
Even now China has continued its incremental open up in financial sector and other areas. It does show that China is much more confident now after seeing Western competitors are way weaker than fear.
Whatever happened in HK or Covid is irrelevant, the West doesn't have a roadmap to achieve what they want and just throw every kitchen sinks to see if anything sticks. Today it is banning investment, tomorrow it is sanctioning Huawei, the day after restricting semiconductor exports. When all else failed, the West would just go back to the first step and re-sanction everything again and again.