Liverpool can have both new and old.
Liverpool has to preserve what it has
Far too many excellent old buildings are still being demolished or left to rot. This has to stop immediately. Introduction of Land Value Tax will stop it, as it did in Pittsburg in the USA
Liverpool needs new buildings blending in with the old.
New buildings can blend in with the old. For e.g., extending the Georgian quarter with only modern Georgian buildings - developers would line up to do that, as they know they would sell. Georgian buildings never went away, they have always been built to that style right up to this day. The worlds first stock-standard house. Style books were made and you just copied them. Many were built in the UK, Australia, New Zealand and North America.
This new development in Aylesbury, by volume house builder Bryant blends in well. although slabbed pavements would have been better
Some new developments have cobbled streets too.
Liverpool needs new modern state-of-the-art buildings
There is lots of spare land that can be used for state-of-the-art modern buildings. Venice is a dead city - it is not active in the commercial sense and has stayed static. De Gaulle feared Paris may end up the same way and reserved land west of Paris at La Defense. No architectural or height restrictions, do what you want. It is the financial district of Paris with lots of residential flats too. It worked. London copied it in the Docklands.
The old dock waterways had old transit sheds, of which most are demolished. The warehouses can be converted to flats, not the sheds. These areas can be made vibrant by building new overhanging buildings as at Hamburg, or direct copies of the Albert Dock if need be. Below Hamburg:
Liverpool needed this iconic building at Brunswick Dock as well. The city foolishly rejected it. It would have been built by now attracting attention from all over the world.