I think it suits the use you are putting it to - probably the same use as everyone does 99% of the time - safe efficient transportation on ordinary roads. Most of us are susceptible to fantasy marketing in vehicles (and everything else) and end up buying too much performance for too much money, leading to anxiety and frustration. Why ? Do we think others will like us more ? Probably not, they'll just be jealous. Maybe we believe others will think we are successful ? Probably they will feel that we don't deserve it, and that we are wasteful. When you drive an older vehicle other people (generally) look upon your car as a pleasant image from their past, and you, as the driver, as a custodian of better values from the past. Especially when you have done the Work your😇self.

I love the old square box Volvos.

B18 engine - I looked it up. It appears there are lots of performance modifications that would make significant performance increases on this engine. Yours is a 60s model, so it's probably carbs or Bosch-D injection, with SOHC. They improved this engine over the years. You could take it up to 130-ish hp with off-the-shelf parts. More with ghetto hotrodding methods.

Maybe some uprated suspension, as it's sagging to the front left when you're driving.

Grew up with the Volvo 140 series. Performance parts can still be had from companies like IPD. If you have a B18, I'm guessing your car is a 1968/69. They're kind, an absolute friend, always there when needed. Easy to work on, service, and if you can keep the rust away they will absolutely outlast us all.