We most definitely should, especially so if you're working in a team or organization bigger than a handful of people. Because it's almost certain that you may need to change or interact with that code very soon in the lifetime of the project. When that happens you want to make sure the code aligns with your own mental model of how things work.

The industry has institutionalized this by making code reviews a very standard best practice. People think of code reviews mainly as a mechanism to reduce bugs, but turns out the biggest benefits (born out by studies) actually are better context-sharing amongst the team, mentoring junior engineers, and onboarding of new team-mates. It ensures that everyone has the same mental model of the system despite working on different parts of it (c.f. the story of the blind men and the elephant.) This results in better ownership and fewer defects per line of code.

Note, this also doesn't mean everybody reviews each and every PR. But any non-trivial PR should be reviewed by team-mates with appropriate context.