My inbox's default retention policy deletes anything that is more than 90 days old unless it has a tag. Receipts, billing statements, messages from real people that I added to my contacts etc all get tagged and retained. Your newsletters, the OTPs, the appointment reminders all fall into the abyss.

But I personally do not like email as a system of record. My response to 'what if I need to know something about the tires' is that I keep a spreadsheet with everything I do to my car.