False. Samsung devices have had good water resistance ratings while still retaining headphone ports. (In fact some of the older models even managed to do so with removable batteries.)
that’s what apple wants people to believe so they believe it. however, it’s not true. for example, the lg v35 has an audio jack (and a high-end audio dac at that) and yet has the same water resistant rating, ip68, as the iphone xs.
Doesn't seem to be an issue with Samsung phones.
"You're holding it wrong"
That sounds like a legitimate reason - they advertise water-resitance and waterproofing for the models lacking a headphone jack.
But.. can't they just make a waterproof headphone jack??
Yes.
Samsung does water resistant phone with their flagship S9. And they still have the 3.5.
And the Samsung S5 has a headphone jack and even an easily-swappable battery, and still has waterproofing.