One of the reasons we bought a used vehicle in 2016 was because we did not like the key-less fob used to start the car and enter it. The electric car entry fobs on our vehicles have been dead for years, but our keys work just fine

Have you tried replacing the battery in the fob?
They generally take typical coin-shaped batteries.

My 2 Fords are keyless entry/start.
Should the battery die, the fobs for each vehicle have an internally-stored physical key to open the door.
Then you place the fob in a special location so that the car can read it (like an rfid chip?) and allow you to drive it.

Whenever I've had a battery go out on me I've always had plenty of warning as it's performance becomes inconsistent or I have to be closer to the car before it will work.
As soon as I notice that happening I switch to the spare fob and order new batteries for each.
Now that I think about it I've only had to do that once and those batteries had already lasted 10 years.

I guess I'm more comfortable with this technology. I follow several automotive forums and I don't think I've ever seen this come up as an issue.