I finally got round to finishing this. I sold my PS4 so I was only able to play it when I went round to my partner's place to play on hers but Covid meant that stopped and I only managed to get up to the end of Chapter 4. Found a cheap PC key a couple of weeks ago and have finished it and just wow.
It's a shame that the PC port is so awful because this is absolutely fantastic. I'm going to dip into Online a bit but I feel like I'm going to be disappointed as it seems like Rockstar only care about GTA V still so this might be ignored a bit.
Also - the Arthur scene where you're riding with the monologues/song playing. Deep. Rockstar really made you care in this one compared to GTA V where I didn't give a shit about what happened to any of the characters.