Parallax Tide has synergies with...

Estrid's Invocation: Keep the original Tide on full counters. Copy it with Estrid. Exile up to 5 lands with the copy. On the upkeep when Estrid will fade away, stack the upkeep triggers with Estrid on top. Blink Estrid first (lands return) and have it return copying Parallax Tide. Exile 5 lands again. This basically keeps 5 lands off the board for 5 turns (until the original Tide is gone). Even better if you get a 2nd Estrid involved.

Riptide Chimera: Exile up to 5 lands. On your upkeep, both triggers go on the stack. Bounce Parallax first. The lands return, but then you can replay Parallax and remove the lands again. Unfortunately this costs 2UU every turn so it's awkward.

Auratog/Phantatog/Seal of Cleansing: Stack 5 exile abilities. In response, sacrifice Parallax Tide to the Atog. Lands are exiled permanently. The "Oblivion Ring" trick works with this old templating.

Propaganda/Sphere of Safety: Opponent can't attack you if they can't generate 2 mana on main phase.

Chalice/Spheres: Opponent has a hard time beating resistors without lands

Replenish: Reuse Parallax enchantments like the old Standard deck

3cc Teferi: Completes the soft lock by stopping instant tricks in the window between. -3 to reset a Parallax on 0 counters.

This deck could really break Parallax Tide. Parallax Wave is decent too, maybe 4 Tide + 2 Wave main?