I think the biggest misunderstanding that always occurs when talking about Scrum and/or Agile is when people from radically different industries meet. From the perspective of my previous team, 1-3 days from PR to prod would be indeed quite long. For such a team, "two weeks per sprint" can seem like an eternity and will only slow things down.
On the other hand, one of my best friends works for the largest insurer in the company. They do about one release per six months and working in two week cycles would be an unimaginable speedup for them. It frequently takes more than a month to get word back from the regulators that their proposed code changes have been approved at all.
Both of the groups ("scrum slows you down"/"scrum is uncomfortably fast") have trouble imagining that the problems of the other group can even exist.
What would you do to go from PR to prod faster when you want at least 1 human who didn't open the PR to manually review each PR in a 10-20 developer remote team?
1 day doesn't seem too bad, often times it can be 2-6 hours. It really depends on what lines up and how big the PR is.
A code review for a smallish change shouldn't take more time than sending a few chat messages. You send them the code review, they look through the 20 lines in the code review tool, note that the changes corresponds to the change description, see that you added tests for it and that those tests passed, they ask you to clarify a variable name, you update the code and send it again a few minutes later, they review the new change and see that the name was properly changed and tests still pass and press accept.
This is how most of the code reviews went for me at Google. If you do a bigger change it will take more time, but I see no reason why smaller should take longer than that. After all you are just sending small bits of text back and forth, it really isn't more complicated than a few chat messages.
The delay isn't always around the review itself taking long. It's having a dev working on their own tickets and then having an opportunity to check in and review someone elses code. You could end up getting a review on your code in 10 minutes or 5 hours based on what's going on for everyone at the time you open the PR. It might even take until the next day and for a bigger PR it could involve a few more eyeballs and time commitment for the review itself (outliers but they do happen).
