Level Cap

Ive just reached level 45 and levelling is starting to get harder again. I’ve seen players on YouTube at level 99 and I’m wondering if it takes a lot longer or if the exp you get gets bigger as you go on.

I’ve also seen people talking about different DLCs and was wondering if you need a DLC to get past level 50 or if you can get past level 50 and it’s just really hard without the DLC.