They were out of power from 1997-2010. They lost all their confidence and became a fake version of Labour, trying to emulate them. Cameron going on his polar voyage and hugging a hoodie was the exact moment it all went wrong.
Most who were in power before 1997 would now be retired, so the old tory party has pretty much vanished. There are so many Blairist lefties in positions of power it probably can't be turned around, at least not without a massive internal fight. So just move on, leave it to die. Perhaps a few people who don't really understand and just slavishly vote blue will carry on, they'll just be the new Lib Dems, a pointless party that keeps going but never gets any power.
Lefties can pick labour or green. It doesn't really matter, there are so few of them they'll never get elected again without the mainstream support they need, which will never return within a lifetime after the completely insane Starmer experience.