The 2019 Open Championship

I'm not sure it will be harder for the afternoon players. The rain made the course much softer and at the moment it's sunny (obviously the rain can come back at any moment).

I heard the commentators say on one of Koepka's shots that earlier in the day his ball would have rolled over the green rather than sticking pin high as it did.

I haven't been watching long enough to know if the wind is much different now than it was earlier. But even if the wind is blowing a bit more, it might be offset by the softer, more receptive, greens.
I did notice that the sun did come out again. And yes, it may be something that will happen off and on throughout the tournament. That is the nature of the Open Championship. It's the luck of the draw. It's rare for the golf tournaments in the US to have weather that varies so much for the field.

The Open is in no way bad. It's just different, and it requires a unique mindset to keep the emotions under control.