Boycott Everything

I've always wondered why Volvo, a car company who pretend to give a shit about the environment more than other car companies, don't offer a petrol hybrid and only sell diesel hybrids. They must have some sort of justification for that...

They do offer petrol hybrids - VB had one, the T8.

The latest diesels are getting pretty good even on the emissions side- its certainly possible to make a very clean diesel using all the tricks they have for cleaning the exhaust up.
The big problem in the recent past was that the tests were not fit for purpose, and so if a car company wanted to push the limits of what was acceptable, they could. VW are the famous example, but then they actually cheated the system, rather than merely designed around it/gamed it legally like most of the others - Nissan are particularly bad from recollection.

The new tests should prevent much of this through being more routed in real world driving than impossible to recreate auto test cycles.

On the climate change side, diesel is significantly better. While a petrol car may put out 200g CO2 a km, a diesel car may only put out 120g. Thats quite a big difference. A well maintained modern diesel may still be the best choice for many drivers.

a car company who pretend to give a shit about the environment more than other car companies

They do? I thought they cared more about the soft squidgy humans in the car than other makers. But I know little about car brands and what they now stand for TBH.