Let's be realistic here people. In a car you've got some protection, whether it works in your favour or not that's another thing. On a bike you have nothing except a pair of "leathers and gloves and helmet" no matter the cost they come an apart like plastic in an impact. Or wait now for u all to tell me I'm wrong there to
Actually, you can get leather suits with built-in airbags that inflate if you come off the bike, and no decent crash helmet should come apart in an impact.
I get that it's worrying, OP, but it IS possible to ride a motorbike safely. DP is 59, and has been riding since he was 16. He had a few minor offs in his first couple of years, but has been accident-free for over 40 years (well, almost - we don't count the one where another bike rolled into him when he was stationary at traffic lights, because he remained upright with his feet on the ground and there was just a tiny bit of damage to his number plate).
That 40 years includes 13 years when he was working as a motorbike courier and doing hundreds of miles a week, week in, week out. I'm a real scaredy-cat, and I have no fear whatsoever about going on the back of his bike. His brother used to race bikes (as did his father) and DP's done track days on really fast sports bikes, too, and is no slouch when it comes to speed. He's commuted by motorbike regularly, both long distances by motorway and through central London traffic.
If your DH isn't a very experienced rider, I'd strongly recommend he does one of these courses bikesafe.co.uk/ . They have a fantastic reputation. They teach riders how to anticipate and avoid potential hazards.