Here’s what worked for me on my ancient iPhone:

1. Open a web page in Safari and click the Share icon
2. Click Options and choose “web archive”
3. Click Save to Files, being sure to choose to save on iPhone (not iCloud)
4. Open saved items in the Files app

Web Archive preserved the look of web pages best with appropriate font sizes vs the PDF option.

Tried several of the feed reading apps suggested but my OS is too old to install them.

My method worked perfectly and helped on a HND to JFK flight.