An avocado also has an order of magnitude more nutritional value. Tomatoes are 95% water with little to show for the other 5%. Avocados have significantly more carbs, fat, and nutrients.

If concerned about water it might be a good idea to start with meat. A pound of beef needing about 7000 liters.

Meat is extremely nutritious. And isn't 7000 L of water but of virtual water. This concept is meaningless as it is for decision making. It's way more complex than that.

I eat meat once a month max, so I got that front covered already I guess.

I agree. The American cuisine suggests meat daily, sometimes even multiple times per day.

Reducing this to a few days a week for enough people could make a huge difference.

I'm in the UK. Unfortunately we don't grow avocados, but we do have the water for it.