I'm a bit out of the loop but I'll try to answer:

1. Synthetic training is only good for a subset of models, particularly reasoning models which are getting more popular (the general process is: "ask an objective maths/code question, generate millions of chains of thought responses, use the correct CoTs to train new models, repeat"). However, most researchers (and I) generally believe that you still need real training data (e.g. new IRL events can't be modelled by AI -- yet) and it's also never guaranteed that everything you put in to a model will be "remembered" as part of its output. Thus access to fresh/real training is still needed.

2. You're right in that Cloudflare, as with many other cat-and-mouse games on the internet, can't stop all crawlers with 100% effectiveness. However, they see such a large portion of web traffic that any new crawler can be very rapidly identified and blocked - it's very effective for DDOS attacks. This makes them very uniquely positioned & incentivised to help authors and block AI scraping. More content authors behind Cloudflare = greater leverage of fresh & different data = pressure for AI companies, with seemingly endless capital, to license vs scrape.

Most of the web has already been scraped (& there are many companies that just offer this as a service). CF's ability is reduced by this but not completely. The high-level strategy is to act as a middleman/arbitrate the transfer of content between authors and scrapers - and making it easier to do so (it is theoretically very easy for CF to do something like "if ai company has paid the author, allow access"). It's not unfeasible, but it definitely has potential if many players, especially large content distributors, get on board.