I'm just going to put this here and step back a safe distance.

I own 4 bikes, only one had internal routing. I am not saying its better or worse but its a PIA to deal with IMO. Nothing easier than external. I will not purchase internal if I can help it but wouldn't stop me either. I just try to avoid it.

I did watch the video for the fun of it but before I even watched it I noticed this guy has what appears to be a carbon Canyon clamped NOT at the seat post? Umm that is kind of a no no. I bet youtube comments beat him up badly for this!

Sram eTap.

Good points. My fatbike has internal routing (except dropper) and also the external brackets, so I could chose either. i had once replaced my shifter cable and housing and it was a pain internally.
Since my frames are black and i have a huge frame bag anyway, I don't think the external cables destroy optics.

The only concern I would have is the limited choice of external dropper posts.

I wonder how much cost and weight is added for the internal routing and the required reinforcements.

Obviously all "nicer"bikes come with internal routing. But does it actually enhance the riding experience? Sure it looks nicer, but now it seems to be a solution in search of a problem.

That Canyon bike he shows has a horrible design and totally pointless holes to hide a few cm of cable.

I refuse to buy bike frames that have internal routing. In a weak moment a few years back I did buy a Protour-level $8k bike with internal routing. The initial build was such hellish misery that when I later had to replace a rear cable, I just hung up the bike to collect spiderwebs. - for 3 years.

Thank God for Chinese carbon off of Ali-Express. You can get standard threaded BB shells, rim brake fittings, and external routing... all the good stuff.

The only positive for internal I can think of is for bike retailers/service shops, as bikes are becoming so user -unfriendly to work on, that cyclists are locked to their shops for every maintenance task.

Is this really something that needs a 13 minute video?

No brakes?

Another useless feature is the lack of clearance between the tire and brake. Diminishing the clearance does make a race bike go faster.

Not me. I didn't make it though 20 seconds.

^+1. I was thinking the same.
I like the guy's "pro's vs con's" but the message could have been delivered in a much more concise manner...
4:36 tops.

its sick biker aka the most boring pointless bike channel on youtube !!!!!

Well, I did sit through the entire video. Nothing better to do on a Sunday morning.
Actually, that's not quite correct, I was looking for ways to put off getting off my butt and getting to the projects I should be working on.
Anyway, My own preference is for external cables, but one of my reasons wasn't even addressed in the video.
External cables enable one to give the shift cables a good firm stretching to firmly seat the housings in the stops, and helps to keep them in adjustment for a longer period after new assembly, or cable replacement.
I have lots of experience stringing internal cable, both with and without full length housings, and yeah, they are a time consuming PITA.(Tri bikes have to be the worst)
But for many that can leave the assembly and servicing in someone else's hands, aesthetics trumps serviceability.

Taking a break from doing taxes and I see this subject come up. How appropriate.

Internal cable routing through the BB is akin to doing taxes. A total PIA, makes no sense, and can't wait to get a way from it.

Only the rear is internal and only goes through the top tube. If you can't fish a cable there, you should never work on a bike.

I explored the channel and kind of felt the same way lol

Cabin fever up here.

Here's a thing I don't like, though: the manufacturer is going to make the decision to put the cables inside the frame, without buyer input. If you otherwise like that particular bike, you're stuck with the holes (or not, according to your preference).

Lots of internal routing these days. They figure out out to get the mechanical routed and can then use that same frame design to put Di2 on as the next model up. Di2 wants internal.

Depends. I have a bike from 1993 with an internally routed rear brake cable. The frame builder (Witcomb of Deptford, UK) brazed a brass tube down the inside of the frame so that passing the cable through is a piece of cake. My new carbon bike has all internal cables and I have to admit I'm not looking forward to replacing the cables. I managed to mess up the front derailleur cable whilst adjusting it and I've been putting off replacing it. I've seen a few tips that should help, though. One in particular looked interesting: using a plastic tube which you put over the original cable before removing it, then you can pass the new cable down the tube. I have a piece of tube which is exactly the right size.