You're one-off job is nothing to be holding up as an example of current web development. My company has 23 active clients and I can't tell you the last time, many years ago, we saw IE8 in the visitors logs much less anything less than that.
Us programmers often get this wrong.
It's great if you never had to deal with them, but that doesn't mean it won't happen.
Note: It wasn't a one-off job either. There were multiple jobs, government sector.