It just creates more and more opportunities for phishing attacks to have essentially unlimited TLDs created where it makes it harder for anybody to easily figure out what is the actual home of any company.
Also, I'm not worried about Amazon or Google or Facebook or Microsoft, but for smaller businesses, they're going to be faced with costly and unnecessary legal battles and challenges over all kinds of trademarks. It's such a waste of effort. It's bad enough when there were just a handful of TLDs that were relevant, but now that we have essentially unlimited domain names all sorts of additional costly conflicts will emerge.
If these new TLDs have to exist, one potential way to minimize confusion and minimize disputes would be for all .com owners to automatically be assigned that respective TLD, so you always automatically know that "icloud.apple" is owned by Apple.com and that "books.amazon" is owned by Amazon.com and if you went and bought "xyz12345.com" you would also automatically own the xyz12345 TLD so these disputes would mostly be already settled. But that's not going to happen because there would be no extra money in that.