A large number of people choose to rent a property rather than get a mortgage with a bank and have a huge dept on their hands lasting many years.
What people find difficult is saving for the large deposit which is required to gain a mortgage. You will need a deposit of around 10-20 percent of the property value which can take a lot of time to save up, unless you are fortunate to have someone to help you out as a first time buyer for instance your parents.
This is a reason that some couples or single people decide on renting a house over buying.
Although there benefits of owning your home there are some things that be a little negative. You will have to prepare for things like interest rates increasing and if something unfortunate goes wrong then it will be up to you to pay for repairs. Also if you want to move home, it can be a lengthy process to deal with and can take several months. You will have to pay an expensive fee also to an estate agents if you go down that route and have them sell it for you.
With a rented property in London you will not be tied down as much, only as long as your contract states which could be around six months to one year. After that, if you wish to move you will be free to do so.
It will be the responsibility of your landlord or letting agent to organise and pay for any repairs that need doing around the house or apartment. Any damage that you make you will have to pay for and risk being asked to leave.