Somewhat a philosophical question IMO.
It’s the nature of a representative democracy that frequently you do not get the result that you voted for. That doesn’t mean your vote was ‘wasted’ somehow: if you hadn’t voted then you would have had even less reasonable expectation of the result you wanted.
The concept of ‘wasted votes’ pertains to our first past the post system and the notion of ‘safe seats’. If you accept that the sitting representative is impossible to remove due to local voting habits, then any opposing vote is sometimes termed ‘wasted’. This isn’t always true though. Safe seats are sometimes lost, often because enough people ignored the idea of wasted votes and tried to use their votes to change things. This kinda covers the other usual idea for a ‘wasted’ vote – voting for something that has no chance. Maybe Lord Buckethead, for instance. Again, one day maybe enough people decide to use Lord Buckethead as a protest vote, and he becomes an MP.
In a democracy such as ours, the only truly wasted vote is the one which is registered but isn’t cast.