Oh that's interesting. Are you saying that PR status never expires?You have mixed up. PR status do not "expired". You will receive a PR card and that card will have an expiry date (usually 5 years).
You will need to make sure that you meet your PR residency obligation (live in Canada at least 2 years within the first 5 years since landing/getting your eCOPR).
You need a valid PR card to travel back to Canada via commerical transport (flight, train, bus, ship, ferry ...etc)
To renew your PR card, you will need to meet your RO and apply inside Canada.
But looks like this page says that we have to be in Canada for 730 within last 5 years to maintain the PR status.
https://www.canada.ca/en/immigration-refugees-citizenship/services/new-immigrants/pr-card/understand-pr-status.html -> under Time lived in Canada
Did I understand something wrong.