Do you have support from your manager on these principles? If this isn't enforced at an organizational level, I understand why he doesn't care to do it, and I would recommend managing up so that your lead/manager understands the importance of modern coding practices.

> Refusing to use version control is a prime example. The industry as a whole has unanimously decided that version control is necessary, but he still argues that his backup of an entire directory that he does once every 2 months is more efficient

For what's it's worth, a lot of people who use version control treat it as a backup system instead of as a record of logical changes to the code base with a detailed description of what has changed and why.

It's still a hundred times better than some kind of a manual process. I can at least view the history of files with good tooling and the build pipeline etc. are manageable.

Git has pretty much killed that practice ("merged PR xxxx" is all you get).

Github you mean. Prior to git, people also did similar things with svn and other VCS software.

He doesn't want to learn the new thing.

Just refuse to accept the code unless it's a PR; leave him no choice.

Already tried. I've been told to just merge it and stop being awkward

Who ever is telling you to accept that is really the one responsible.

They're the one setting the standards for the team. Your colleague is just working to rule and the rules are lax.