I mind a public access website for a government entity and this is exactly the pattern I see. US residential IPs make a couple of requests then never come back.

The bots may have layer 7 signatures that make them "easy" to block, but I'm dealing with COTS software with no ability to make changes to the stack. Even if I could by the time they're blocked the work is done and they're never coming back anyway.

I don't think I'm seeing the LLM bots in the scraping on this particular site. This site's data is highly sought-after by data brokers, legal services advertising, debt collectors, etc. I tend to think I'm seeing homespun scrapers. This site has been up for 20+ years and the scrapers seem to be well-adapted to using the HTML as an ad-hoc API for the data. The difference in the last few years has been the availability of vast numbers of residential proxies to mask the traffic.