Starting in the '70s, we began to see beautiful singers who could also perform the music beautifully being cast in these roles. It makes the story more believable for the audience. Speaking of believability, opera plot lines have a reputation as being somewhat fanciful. If you want realism, Stewart advises you do your homework before buying a ticket. Do some research, seek out the more believable stories.
Many operas have more realistic developed characters than some of the stereotypical opera roles.
There are many operas that are more accessible to the general population. The sets, the costumes, the whole performance will draw you in. Opera is very entertaining. It's fun to go because even if you have never been there before, you will recognize the music or the plots. If you've seen an episode of Friends, you see what is borrowed from LaBoheme.