Some roses, just like your Queen Elizabeth, don't need to be grafted to be vigorous roses when grown own root. It's just that common practice at the time was for most breeders to bud the roses for testing.
A little known fact is that Buck's roses are virused, but they don't seem to mind and just keep on being good roses.
The problem today is that many roses that were once budded are now being offered only own root and have probably never been tested to see if they are good garden roses own root. There are going to be a lot of roses sold in bands that fail and people new to rose gardening are going to be telling themselves that they just can't grow roses when it's not true.
Smiles,
Lyn