This is an exceptionally smart outlook; and reflects my own experience - if something is wrong in my code in Safari it is usually wrong elsewhere.

There's an important and cool concept here about using the weakest link sometimes.

Similar example: as an app developer, I intentionally use a phone several, several generations behind so I can see what the actual response time and general UX feeling is on the devices frankly a lot of users are going to have.

If my app runs well on my iPhone 8, it's obviously going to scream on a 12.