Tubs in shower space, does water not go under tub

[Sam P.]

I’m looking to remodel a bathroom and seems like the new modern way is a double shower head on both sides with a tub in back. In a small setting does water does seep under tub which could cause a bigger issue? I know you can put some sort of sealer between tub and tile but seems like I haven’t seen that at houses I’ve toured and might take away from the slick look.