Problem with AV receiver is the cabling. If you move around often then it’s a lot of hassle, whereas these wireless systems provide convenience. End of the days that’s why they are popular and something like the Sonos Arc being one of the most popular AV systems in the market.
Very true but a lot of people prefer the convenience of a soundbar setup.
Take the £799 you may or may not be about to spend and put it towards a proper sound system. Not only will you get superior sound but when technology advances all you have to do is upgrade the AV Receiver.