I think we can pretty much agree that all the different SOPs regarding taxi, applied by various airlines across the world, have had their fair share of thoughts put into it, and all have their pros and cons.
I like my company's SOP to let even the youngest FOs do almost everything (except RTO as per Airbus proc, and high velocity crosswinds) on the first day, obviously under supervision from LTC initially then regular captains.

I'd feel quite uncomfortable being upgraded as PIC and have to learn something "as basic" as taxying an airplane though.

^^^ what he said.

I do not get this. Everything in the flight-deck is done double-stitch style. One executes, the other watches. When released for the first solo, were we not allowed to taxi then, un-supervised? Would there be a test exercise after those 1000 hrs to evaluate their (never practiced) taxying skills? Hope many would agree that whenever taxi gets seriously demanding it's better that the responsible PIC has a chart at hand and is looking out, delegating physical steering to the other cockpit resource.

It is understandable that different airlines have different policies, the foundations of which may had been laid down eons ago. Different airframe configurations and trying to have a single shared concept across fleets must play a role. Having acknowledged that fact, as long as the installed controls allow, the work assignment should be completely symmetrical. It's 2020. Even with new colleagues with less than 250 hrs total time it's not a problem (assuming at least late 80's design of the A/C). Clearly, the responsibility and authority of PIC rest undivided. Hence the actions and maneuvers that require (unlike taxying) experience and immediate command judgment remain pegged to the LHS.
In my world that would be:
- fuelling decision
- aircraft technical acceptance
- loadsheet verification
- close the door authorization
- choice of deicing
- RTO stop/go call
- narrow or short runways
- BA medium or worse
- LVP

I believe the RTO = PIC is not a handling debate but a one of authority instead.

F.F: same I had in mind. The CPT has the final say and signs for it.

The reason RTO is not shared, I suppose, is that once executed by an F/O there is no final say left for the PIC. Would not have any issues with accepting an F/Os call or action, as long as they had been trained for it. The chances of screwing one badly are not that dissimilar.

I am very pro F/Os taxiing, see my second paragraph of #21.

I was thinking of the cadet who has only flown a Cessna SEP for 120 hours, then ‘the next day’ finds them self in the cockpit of an A320 as their first commercial type. Taxiing from day one, as well as flying would be a big ask, until the cadet has got used to the airport environment, signage and cues etc. As 2 stripers, we taxied BAe146s in a previous airline, but had all flown turboprops in the same company first, so were used to commercial airports and flying.

Yes, in the next company we had 6 or 10 sectors of taxi training, before being allowed to taxi an A320 !! And most of us had thousands of hours TT by then.

What is difficult about taxying an aircraft?? I'm amazed what strange variations there are in the airline world. Surely if you can't be trusted to taxi, you shouldn't be flying the thing! (obviously helps if you have a RHS tiller! All my companies fleet were so fitted)
A good Captain should delegate as much of the decision making/operation as possible, on their F/O handling sectors. You are of course, as Captain, the final arbiter.

Noted and agreed, there was squat nothing I could have added to the second one.

I've had only 1 or 2 sub-250 hrs, not a problem. At worst you point a finger where to go. Keeping the R/T coherent on a busy day in France is 10x the challenge - best mitigated making them PF :)

About a two dozen in the 500-1000 range, impossible to tell the experience level by the performance. With SETI yes, there'd be a difference.

From day 1 line training if it was “my” sector i taxied and even manipulated the flight controls until taxi at the other end.
how b@##£( difficult can it be. Ok I couldn’t reject a take off until I was released onto the line!
Maybe this would not have been a good idea without a tiller on the rhs but seriously what’s the big deal.
On day one of line training I could have manouvered an aircraft as 360 at 100ft without breaking sweat, 20 plus years later I am not so sure as the system has degraded my skills significantly. Yes I know part of that is my fault......