Talk about a thread drift.
I'm nearly 62 and it is I who is awake at 10,000 ft in the climb on a 6 hour night sector leaving at 01:00 hrs. (F/O Snzzzzzzzzzzzzzz) This is after stating that if you are tired in the cruise please tell me and we will have controlled naps. Happened twice in the last two years.
Told to take up the hold over the airport VOR. The senior and young F/O repeatedly tries to enter in the FMC (its not sequenced in the legs), I have a brief go (failed) so say just do it manually (I meant twiddle the heading nob). At this point he just said to me "you have control" - and this was on exact direct entry to the hold!
Countless other stories, most regarding basic handling problems which should have been sorted out before the F/O's reached 3000 hors.
At 62 I do believe I am still doing the public a service. Whatever, they are still paying me for it so I must suppose they believe they are getting some value.
It's a young mans game and not for old f@rts like me.
I would have to say that you have to make the call on that personally - as you obviously have done. However do not generalise in age or anything else - you may be surprised just by what some other people are capable of.