I should like to stress that I am not one of those people that is of the opinion, "If it's less than 5%, it's no good." Indeed, this is one of the reasons I let my CAMRA membership expire many years ago. I got tired of the CAMRA Ultras who get obsessed with this kind of thing.
There are plenty of good session beers in the 3.4 to 4 percent range that are very good and full of flavour. I would also defy anyone to tell me that Orkney Dragonhead Stout, for example, isn't worth considering. At 4.0%, it is a deep and tasty stout that has all kinds of flavours bursting through.
Even so, I believe a beer needs some degree of strength. There was a bit of a fad a while back for 2.8% beers. I tried a few, but found them very thin indeed.