The Natural Philosopher wrote:
I think where I would install a combi is a bachelor flat of small
dimensions, with a single occupant and a single bathroom there I can see
the virtue of the very small foot print. And overall heating
requirements are not huge.

We stuck one in a one bed flat, two people.

The space saved by not having a cylinder meant we could move the washing
machine out of the kitchen, which made space for a dishwasher. Which
solved the dishes problem. We vented the boiler through the roof, which
meant we could put it in a big cupboard.

Still couldn't shave while my wife was showering, but other than that it
was great. Including the shower. It had a 5 litre heated store for
proper instant hot water, which worked well.

Once you get to a family situation, I think the approach loses all merit.

Absolutely.