What effect would it have on one liners and golf? What about existing strictless scripts?

You don’t have use it if you don’t want to and clearly many don’t for both good and bad reasons.

I’ve seen code with it commented out in a desperate attempt to get some monster of a script to run and it always makes my heart sink (if they’re prepared to do that what other crimes have they committed?).

I think I would be cautious about changing a significant default after 10 years.