I don't feel like I have to wade through anything. The most popular items are usually what show up top, and those tend to be decent quality.
Granted, there are some categories of items which are not good to buy from China, because all the listings are of the same few cheap crap products that overrate their specifications. But those tend to be categories of items which are typically quite pricy, and only the cheap crap variants are available from China, you'll rarely find products for hundreds of dollars on AliExpress, obviously those types of products are better to buy from Amazon or similar, if you are willing to pay the price for a good one.
For small items which don't cost a whole lot to make, AliExpress is perfect.
Never had an issue getting a refund on AliExpress. In one case, I settled for a partial refund. It was one of those fake RCMloader dongles, which technically works, but just doesn't have the same functionality as the original. It didn't seem like anybody was selling the original (maybe they aren't even being manufactured anymore), so I didn't really see any better option, otherwise I would have kept asking for a full refund and tried to buy the original from a different seller. The dispute window was already closed though, so I was relying on the goodwill of the seller, so I didn't expect I would have been able to get a full refund.
In every other case where I had issues (one package arrived opened and empty, some packages never arrived, and a n3DS XL battery that was faulty) I got a full refund without much trouble.
Sometimes they will refuse the refund at first, but they always give you an option to provide more details. This happened in the case of the n3DS XL battery, they refused at first and asked for a video of the console not working, which I provided, then seller asked me to do it again but show the battery installed in the non working console (and AliExpress sided with the seller on this), which wasn't really easy to do because my cousin had the battery and doesn't have a small enough screwdriver, but he managed to get one of the screws out and make another video that was too unclear and dark to see the printing on the battery at all. Still, I uploaded the video to AliExpress, they accepted the refund and I was refunded in a few days. I didn't honestly think that video was going to be good enough and the dispute window was closing, but luckily they accepted it.
If you took too long to complain it could be difficult to get a refund. Once the dispute window is closed, AliExpress don't want anything to do with it anymore, and you're relying on the goodwill of the seller. It's the same on eBay too though. You should never mark an item as received until you have tested it enough to confirm that it's in good working order. Once an item is marked as received, you have only limited time to file a dispute, I think it might be 2 weeks (the item will be auto-marked as received after a few days if the item is sent with international tracking though, once AliExpress' systems detect that the item was delivered from the tracking info), but as long as it's not marked as received, you have until the end of the estimated delivery date + the same 2 weeks.
If it had been months after you received it until you complained about it, understandably AliExpress would not be very willing to give you a refund at that point. They only hold the money for a certain amount of time (same as eBay), once they release the payment to the seller, they have no way of getting that money back, and if the seller is not willing to give a refund, it would be money out of AliExpress' pocket if they gave you a refund against the seller's wishes. That's why neither AliExpress nor eBay is willing to help out once the dispute window is closed. That is not AliExpress or eBay's fault.
They don't operate the same way Amazon does, which will basically accept any return, even fraudulent ones, and take the money out of the seller's profits. This is good for consumers, but bad for legitimate sellers, and the only thing that makes it worth it for sellers to continue to sell on Amazon despite the losses due to fraudulent returns and refunds is the huge exposure they get through Amazon and the fact that Amazon takes care of a lot of the logistics for them, which makes it way easier for small businesses to sell things. As a consumer, I like Amazon's refund policies, but I can understand that from a legitimate seller's point of view they might be a pain in the ass, so I can't expect every online marketplace to be like that.
Chargebacks are meant to be used against fraud. It's pretty typical of any online store or service to ban accounts associated with chargebacks, because it implies the account was involved in fraud, and that is a reasonable action to take to prevent further fraud. Nintendo does the same thing, FWIW.
This was not fraud. The seller didn't intentionally sell you a flashcart with faulty PSRAM, and it sounds like you were aware you were buying a clone cart. So I would say you abused the chargeback system in this case. It's not there for you to use to get a refund on products you are not happy with. It's there to protect you against people who intentionally scam or defraud you.