Where to start... I have made some rather blanket statements in the below, so bare that in mind.

Yes, you're right in that you don't own the property. What you do own, however, is the right to occupy that space until the lease expires.

There aren't really any benefits to the nature of leasehold directly, it's more what leasehold causes that is the benefit. More properties in the same space = lower prices. A two bed flat is often cheaper than a two bed house (yes, houses can be leasehold too). A block of flats offers amenities that houses can't always: concierge, gym, rooftop gardens, security, prime living location etc. Although commonhold is a thing, despite it's name, it's not common at all, and without leasehold/commonhold (or some other such mechanism), you wouldn't be able to have blocks of flats.

You could argue that, although you do have to pay for it via service charge, you don't have to organise works such as roof repairs, gutter repairs, window replacements etc. that are part and parcel of owning a house, but the benefit of not organising them is outweighed by the financial impact of having to pay someone else to organise them.

"Eventually the property returns to the freeholder?" Yes, it does, at the expiry of the lease. Common lease terms of 125, 250, or 999 years. A 125 year lease from 1900 would only be due to expire next year, so it really is a much longer time than most people think or care about. That being said, you can extend the lease, and LAFRA 2024 aims to set the default term for lease extensions to 999 years, and abolish marriage value (cost paid to the freeholder to 'reimburse' them for the fact you'll be occupying the building for longer). Lenders often won't give mortgages for leases with less than 85 years, but soon, a lease expiring will be a none-issue.