Decisive majorities, in my personal opinion, is better. That’s just one school of thought, on the continent, the prevailing belief is that politics by consensus is inherently more desirable.
Like most things in politics, left or right, FPTP or PR, there is no definitive correct answer. Different things work for different countries and their political systems/traditions.
I’ll reiterate the point that, whilst I didn’t vote for a Labour government, it is desirable that they can carry out their ‘mandate’ (however weak or strong) without barrier. In a PR environment, I genuinely believe Brexit would’ve deadlocked the country more and risked a lot more of a toxic political environment and culture. As it happens, the 2019 GE delivered Brexit definitively - even if I personally didn’t agree with it in 2016. In my view, this shows how dynamic our constitutional settlement is.
Of course this is just one school of thought.