This gets complex, becuase different roles/titles have different statuses and removal processes.
Some have been actually removed. Others (which are the ones presumably that you read about being hard to remove), really are hard to remove.
There was a deliberate sleight of hand to handle the remaining ones, giving the impression of being stripped without actually doing that. It’s also pretty arcane because there isn’t much precedent.
But ‘removed from the roll of the peerage’ does not mean removing a peerage.
Andrew is still Duke of York, as only parliament can remove or extinguish a peerage and it has not done so. The ‘roll’ is the sleight of hand. It is about who can be called by certain styles in certain documents.
It was the fudge that worked for what was required.
But Andrew is still a duke. If hereditaries were still in the Lords he would still be a voting member, for example. If he has a son, his son in time will become a duke.
He’s still a counselor of state, too. The fudge there was to add two more (Anne and Edward) so that Andrew would never need to be called upon. But he can only be removed as a counselor of state by parliament, and he has not been so.
Maybe a similar fudge could be come up with for the Line of Succession, whereby he’s not ‘referred to as’ in the LoS. He would still become king though if everyone else dies.
And changing the LoS is far harder than just passing UK legislation (at least if you want to avoid splitting the line).