^^^ this. But this requires capital to even begin. I've considered buying an apartment in a country way cheaper than where I live, and AirBnB'ing it, and paying someone to manage cleaning and key exchange.

In some countries you can get a central apartment for $35k, and a normal wage is $600 per month. If you manage to rent it out on AirBnB for $6-700 per weekend or so (what I paid for an AirBnB in one such country last week with 5 people in a large central apartment), you could make nice profits.

Even renting it out to someone over long term would be profitable; lower profit (potentially) but less risk (definitely)

Renting is negative cash flow for years, in most markets. Its an investment, but you have to start with significant cash.

Other than the fact you need a hefty amount of starting capital.