It's definitely personal choice / for-yourself thing.
For me, I think it's fine to change things that are specific / personal. I have plenty of modifications for dev work, staging, etc.. but also refer to things like Corp.com (https://krebsonsecurity.com/2020/04/microsoft-buys-corp-com-...)
Google.com to DuckDuckGo.com is an exaggeration. I don't think people should redirect MSN to CNN; that's just confusing.
I think it's fine to redirect amazon.co, amazo.com, amazn.com to amazon.com. Could a unique site named "amazn.com" exist? Yes, but I would prefer it to go where I expected. Similar/typo URLs are often related to malware (but not always).
I seem to remember localhost.com had a landing page telling users "You mean to go to localhost".
But yeah, don't use this if you're afraid to redirect your own hosts. If you're like me and want to type "HackerNews.com" because you prefer it landing here.. then use the script.