You probably will need v4 "connectivity" (in quotes because NAT is not more than a mockery of connectivity, compared to the real deal) for at least 15 years. The interesting phase is when v4 address space, which costs a lot to get (the free supply is out, so there is a second hand market) today will go down in price. Then, we're really in legacy mode. Today there is still way too much v4-only infrastructure on the net. Like Eevblog...
Sorry, I have a little stone in my shoe to take out:
... which means if right now I would have only IPv6 I could not reach Eevblog because it is IPv4 only??
Viceversa I am now 100% IPV4 so I am missing today all the website/server on IPV6?
If you had
only IPv6 (without a carrier NAT or similar) yes, then that would be the case.
If you had v6 plus NATted v4, you'd do better.
The latter is -- for reasons of backwards compatibility -- the most common case where there's v6 today.
If you (which is quite more common) are on v4
only, yes, you're missing out on the v6 Internet.
We're running a Hurricane Electric tunnel for v6 at home. It sucks more these days, because low-cost ip geolocation services for that prefix block now thinks we're in Russia. Google gets it right, though. Supposedly they've got enough internal data to determine that themselves.
I've got a Swedish /49 routed over my two tunnels, so will try fixing that soon. However, getting change management approval at home is a pain.