I dunno, I have both
Pickguards are nice once you get your picking hand familiar with it & it works as a guide, to orient your playing without needing to look at your hand.
Likewise without: I get used to using the pickup rings instead, as a guide to rest a finger on.
Actual funcionality as a pickguard: It would make more sense to me to be ABOVE the strings, as I tend to hit the body more above the low E string, while using a pick.
Not having a pickguard & all that free air kind of feels like "going commando" and not wearing any underwear. Sort of liberating in a way
I don't know if I have a preference. I do really like the old wooden pickguards Heritage used to use.