Dealing with low London yields

Hi

First time poster here, thinking about buying a B2L flat in London.  I have looked at lots of property/B2L blogs etc. and most of them talk about looking for yields of 7% and higher.  I am assuming this means gross annual rent / property purchase price including costs.  When I look in my target area (SE1) the best I can see is properties with yields of around 4%.

I am trying to make a decision about whether these yields are just so low that it isn't really worth investing.  After costs etc I can't see that I would earn more than £2-3k pa on a property worth £600-700k, and this would be wiped out if anything disastrous happened.  I feel that I would have to see the investment as essentially a bet that property price rise.  While I am pretty convinced that holding real assets like property is sensible at times of high inflation, it still feel like a big risk.

Any thoughts from the big property brains out there with properties in London?

Many thanks