I don't know a single website owner that is hostile to any search engine web crawler, unless that web crawler is slamming them with so many requests they're effectively getting DDoS'd.
I'll also add plenty of sites don't block any engine but confer special privileges to google bot which depending on the site and their size are almost the same thing.
Edit: And I'll add to limit confusion Reddit hides the sitemap and denies access there's is not an outright ban -- it just makes it a lot harder.
They are part of the story of why Google is degrading, not why they're doing well.
https://support.google.com/webmasters/answer/80553?hl=en
So unless you have a google domain your sol, it's also just generally frowned upon. We have our own UA WhizeBot with an email contact so you can let us know if our crawler is doing anything you'd rather it not.
There have been a few legal cases that protect scraping publicly available information on the web but we'd rather follow robots.txt to avoid the potential for shenanigans in any case.
'Faking' the UA is much more likely to annoy site owners and end up with a permanent block.
You also have bots that seem to be credential stuffing, bots that seem to be content scrapping (stuff with same typos shows up elsewhere after their visits, really obvious on new / fresh articles, bots that seem to be exploring for copyright claims, rando bots (maybe comment sentiment analysis for stock trading) etc.
Google is much more welcome by comparison.
Generally I wouldn't qualify a lot of those as search engine web crawlers but more web scrapers looking to re-use data, not just surface it.
Like I said in another comment, if you’re someone that just wants to surface Amazon results they love you. It’s the people that want to take advantage of amazon data in some other way they’re trying to stop.