"I'm not a virologist, but surely the more we lockdown, the longer we draw out the pandemic?"
No, the more we lockdown (and the harder we lockdown) then the shorter the pandemic.
If one person gets it, and immediately isolates - or isn't surrounded by other people, then the virus inside the ill person has nowhere to go. As they fight it off, it just dies. (Or if they die without passing it on it also dies). It needs people nearby to infect, and if most of them are at home, then it can't do that.
If we just let it keep infecting more and more people, every time it goes into a new body, it has the chance to mutate into another version, so then it can drag out the pandemic.
Plus you're looking at millions of people dying, and even more millions of people with long Covid if you let everyone get it. And that's without even counting others affected by hospitals being overrun.
The vaccines do work, if the government properly buys and distributes them, and they work on various versions of it so far, which is great. And there are vaccines going out globally, so hopefully we can beat this thing with as few lives lost as possible. But until the vaccines can be rolled out to cover more than a certain percentage - is it 70-80% of the population? then we need to stop it spreading.
I wish we would have a proper, hard lockdown to get numbers down much quicker - but the government doesn't seem to want to fund that.