I cannot see any reason why you wouldn't leave those long, thick canes as they are - they are providing a nice structural framework, not too many and not twiggy. I usually aim to have exactly that sort of finish after pruning, keeping half a dozen long canes and pruning all the laterals back to a few inches.
Of course, I am not any sort of expert and am also notoriously slack with pruning regimes (well, any sort of regimes, really) but those canes look healthily productive. If the flowering started to deteriorate....or disease was a big pressure, then maybe a bit of thinning, to 4-5 long canes....but otherwise, I cannot really see any reason to remove any of them.
My eyesight is a bit dubious - what is the twiggy growth in the middle - is this another rose or part of the same one? That growth does look a bit weedy and twiggy but cannot see enough to be helpful.

Only take out canes at the bottom if you don't want that cane. What you can do now it trim the laterals that are coming off of the long canes tha you have tied into a curve. That will neaten it up a bit. Also, when its done blooming you can do the same, trim of the small canes that produced the flowers, not the main canes.

It's just a baby.

Downside of NOT pruning, only one I can think of would be if a cane is able to injure someone walking by. Safety first!

I don't do a major pruning of climbers every year, only every three years or so, with just a light or moderate clean-up in the off years.

Climbers, in fact, most classes of roses, need very little pruning, just shaping and removing deadwood. Hybrid Teas are the only roses that require heavy pruning--and even they can live and bloom without it.