Wow. The UK link you provide is running at about ~$7.65 per watt. That's extreme/exorbitant plus their tiles look ugly and I doubt the resell value on the home will be as high as a Tesla Solar Roof (since aesthetics are king on homes).

Currently, even in Cali a solar system ranges at about $4-5 per watt. The cost to redo a roof depends on the size but almost certainly it would be cheaper than the extra $2.65-3.65 watt left over on using a conventional system and less long-term liability to homeowner to replace a roof and do conventional solar.

Also, let me further point out this system was a 2kw system which isn't enough to fully be energy independent as a home owner. Sizes range in the 5kw to 8kw, at least in the USA. So, that would add additional money into the equation and only further emphasize my statement on 'that's exorbitant'.

UK homes use far less electric than the US, and air conditioning is almost unheard of.

Commonest UK size for solar is currently 3-4kWp, which is plenty for household independence, and above 5 or 6 rare. Earlier systems were smaller as panels were costly. I think somewhere around 5 is the point an installation is considered commercial rather than domestic making larger even less attractive.

Exorbitant or not it pays based on UK electric prices and feed in tariffs.

Price-wise I think that may be a decade, perhaps more, out of date as they link to a long replaced grant scheme.

No idea of current prices, and Tesla are available here too. The couple of times I've seen solar tiles in situ (like I say, not common here), have been far more like the last photo than the first which stands out.