My wife and I bought a 2020 XC60 T6 via OSD, overseas delivery. The T6 cost about $3k more, a small sum we thought. We wanted a bit more hp on tap.
I discovered while learning about the car that the supercharger disengages at steady state driving. Makes sense. The supercharger disengages completely at about 3500rpm, when the turbo takes over. The way we drive I doubt we'll get much use from the turbo. I'd rather be running a small supercharger at lower rpm than a turbo. Less heat build up in the engine compartment. Superchargers can last 150K miles, turbo's likely not depending on many factors.
Volvo uses a top quality Eaton supercharger and Borg Warner turbo.
I can't attest to prospective reliability of one over the other. I'd go for the T6 option. The supercharger produces a steady, even stream of pull. Combined with gearing. direct injection and the over square engine the acceleration is quite smooth and strong.