Construction costs are currently skyrocketing

Pretty much a strong router centrally located - done.

So nominally all routers or rather: the access points installed there are equally strong because it is legally mandated, and this is also confirmed in practice if you pay some attention to the positioning of the antennas. In a typical single-family home on the market, that means coverage ends at the latest on the upper floor, because the worst for the range besides reinforced concrete and glass is the underfloor heating.

Fritzbox and that's that. That comes from cheap routers. Our Wi-Fi runs extremely stable.

Ours too, although the devices used are repeatedly criticized for their poor Wi-Fi performance. It's not always just the hardware and software. ;)

Pretty much a strong router in a central location - done.

That's how I have it now too and as I said, I've never had a problem with it, even with 4 kids simultaneously in Teams / Zoom, me working from home and my wife surfing and streaming

You are probably aware that the transmission power of Wi-Fi is regulated by law and that is a good thing. With a central router, you will only be able to use your 5 GHz network in the immediate vicinity. For the rest of the house, there is only the slower 2.4 GHz network. If you rely exclusively on Wi-Fi, you should always work with access points to have good Wi-Fi coverage throughout the house.

Not everyone can recognize the difference between HD and 4K on the TV from x meters away. The WLAN-independent issue of micro stuttering on old and only rudimentarily compatible hardware (TV devices) is even more difficult. Many people simply do not notice or see this, or they do not care. Just as expensive music systems and speakers don't matter to me, the built-in speaker is enough for me. :D Anyway, the expectation strongly correlates with the acceptance of WLAN for everything.

The problem is as follows. Technical developments are progressing so quickly that you can no longer plan 10 or even 20 years ahead today. So who had Wi-Fi or a mobile phone 20 years ago? Certainly very few. No one could have even guessed that Magenta TV would exist one day.

I think it is important today to install enough empty conduits for future applications. In floors, walls, and floors.

What is being discussed now are cars with bidirectional charging functions. Water heating via photovoltaics. Possibly in 10 years the electric car will take over the function of the public power grid. Anyway, applications will come that are unimaginable today.
You can’t really plan much for that. Just a few years ago, telephone and SAT sockets were still installed. Today it is LAN cables.
And in 50 years everyone will have a rocket launch pad in their front yard and jet off to Mars on the weekend. Elon Musk leading the way.