Where to now for long term investors of Telstra, page-777

You're only looking at (the speed) part of the equation (ignoring the volume part) and then drawing incorrect conclusions.

The Fibre provides speed and capacity (provided it doesn't rely on the copper access to the home as you correctly point out, which is one of many reasons why the FTTN instead of FTTH was such a spectacularly bad decision IMHO).
The Fibre itself is likely (and was intended) to support incremental growth in transmission speeds, much like use of the Copper access has expanded beyond it's original purpose.
5G might support acceptable speeds for many applications but there's little reason to suspect mobile will ever be able to support the speed at the volumes required.

This point is amply demonstrated any time you're trying to use your mobile for data in a congested area. We can expect incremental improvement in mobile transmission capacity but this won't solve the problem as it's only reasonable to expect that growth in data wants/needs are likely to increase at a comparable rate.

I'm sure many won't like the comparison but using FTTN is a bit like telling half the population on the introduction of the telephone that they'd be stuck with telegrams for another 15 years. The political climb down will be gradual (and expensive) but IMHO 15 years from now most affluent areas will have FTTN whether they get the connection for free or pay for it themselves.