The UK high street has been a notable victim. Gradually, over the past couple of decades, company after company has been snapped up by PE. Not just shops, but restaurants too. Suddenly you realise that the 5 or 6 high street chains that were competing are now owned by the same fund. Quality collapses, prices rise, not just at one chain but everywhere. People stop going, the chain collapses, another empty unit, the fund moves on. It's easy to point at Amazon and internet shopping as having degraded the British high street, but there are several other factors, and PE is a big one.
PE is often just legalised larceny.
Same for Amazon vs going direct to the manufacturers, which is more often than not, China.
That comes with a bunch of problems. Taxes, import duties and import refusals are the biggest one. With Amazon, at least as long as it's sold or fulfilled by Amazon, no matter what, you are going to get the product in a reasonable time frame (1-3 days IME).
Shipping... depends. If you're in bad luck, the seller doesn't ship Fedex or DHL, but Yanwen or another one of the usual bunch of "aggregators" that bundle weeks worth of shipment to forward it to the US or Europe and unbundle the shipments there.
Assuming your product shows up at your doorstep, legally, you are now the importer and fully responsible for anything related to that specific product - say, an electrical appliance that sets your house on fire. You can't hold anyone accountable but yourself.
And finally, if there's defects, you only have to deal with Amazon. Free shipment back, done. With anything straight out of China, you are now responsible for shipments.