it’ll very much be the back up and I cant see it being used that much if at all, it’ll be a bonus when the house gets sold is all

No it really isn’t a bonus – if it was a good thing then you’d see downstairs showers in lots of houses including new-builds…. which you don’t.
TBH storage is key in most houses – a tall shower sized cupboard would be way more use!

I see the chat about electric vs boiler for pressure, I’ve experienced both where its like a dribble out of a straw, I assumed the pressure was all down to the water pressure coming into the property?

Its also about flow rates.  a 10 kw electric heater can only heat 1/4 the amount of water as a 40 kw gas boiler so you only get 1/4 the flow rate

What about new houses which aren’t going to have local gas boilers? Assume they will have electric showers?

Most likely they’ll have pressurised tanks which could be heated by solar thermal, heat pumps, gas boilers or immersion heaters.

Its also about flow rates. a 10 kw electric heater can only heat 1/4 the amount of water as a 40 kw gas boiler so you only get 1/4 the flow rate

Indeed. It’s all good news really.

Save water save energy get clean. What’s not to like