It's obviously quite hard to hit a fast moving object.
But even with /tick freeze you just cannot interact with the minecart at all.
Hitting it doesn't destroy it nor damage its passengers.

Reproduction Steps

• Build a loop for a minecart to speed up in
• Set minecartMaxSpeed to 1000
• Do tick freeze
• Try to hit the minecart

Observed Result

• You cannot destroy the minecart
  tick freeze(1).mp4

Expected Result

• You would be able to destroy the minecart

Suggested fix

• This is probably due to interpolation. I think the best way to fix this is remove entity position interpolation (show entities real position) during /tick freeze since everything is stationary so there is no movement to interpolate. To prevent entities appearing to teleport when /tick freeze is executed you should still interpolate their movement from their current position to their true non-interpolated position for 1 pseudo-tick after the command is executed instead of abruptly removing the interpolation.
  Of course only remove the interpolation for entities which are frozen by /tick freeze, player movement should still be interpolated as normal.