Firstly, as explained under Legalities, leasehold is a fully legal ownership form for foreigners, see Legalities.  Secondly, leasehold makes a better investment compared to freehold property.

A good investment has the highest possible rental income for the lowest possible investment. This can be better achieved with leasehold property than with freehold property.

Freehold property in a top location with good rental income is very expensive and therefore the initial investment is high.

For the same initial investment, it is better to buy leasehold property in a top location with excellent rental income than to buy freehold property in a less popular area with limited rental income.

With long term leasing in a top area the initial investment is relatively low but the rental income is very high. Therefore, the initial investment is earned back relatively quickly.  Even with moderate owner occupancy it can be estimated that rental income will fully pay for the investment in 10 years, with 25+25 year lease the investor has then up to 40 more years of free cash flows.

The value of property in a popular area is steadily increasing and it is easy to sell the property again.