This is why they have “Forever” stamps. To cover the cost of postage even 50-100 years later.
The United States Postal Services have never, to my memory, been so expensive or unreliable.
By fdad, who was born in 1920, marveled about how a letter sent in New York City would often arrive anywhere in the 5 boroughs the same day.
NY-CA? Two or three days, but certainly under a week.
Soon we’ll be like Mexico, where 50% of packages and almost as many letters never even arrive.