Yes, you need to have some. But the barrier is getting lower by the year, even for International travel.

For example:

San Francisco <-> Milan, May 7 - May 20, Norwegian Air+Easy Jet: $598.

Air Bnb for the duration: Central Loft, $70/night, 13 nights, $910. (you can find much lower as well, if you want to go for the minimum).

Shop local, cook & eat in the apartment, $20/day? $280.

Spend 13 days walking and exploring Milan for under $2,000.

That's not a trivial amount, but it's not the $2,000 air fare and $150 night hotel and $50 day food type of money, either.