I don't think there are enough skills for either. My average table tends to be in the 4-6 player range with each player getting about 4 skills or more. 5e has a total of
Right off the bat almost any given PC & probably the group can dump athletics acrobatics or both with no cost bringing that down to 16. Then You've got the C tier skills like sleight of hand animal handling nature & possibly
history nature and/or religion . All the group really needs is perception arcana stealth a social skill & maybe stealth/insight but that's a small enough pool where almost any one player can have all of it making it a thing that all but the smallest groups are going to have even without trying to coordinate.
With so much leeway there's no loss if bob is forced to do without due to duplication, but even that doesn't happen.
Take this example:
- Bob's class gives him an option to pick two from A B C D & E (he picks A &B because C D & E is pointless to him for whatever reason*)
- Bob's race gives a choice of 2 between D E& Q
- Bob would never pick any of those and has no interest in them so they were never actually in conflict simply by being offered by two sources
- Under the current rules Bob picks the S tier skills of α & Σ from race even though none of those were options & he was never out of choices he could choose instead. Bob can still pick from C D &Q despite already haven chosen A & B
The rule as it exists has no reason to exist because there is no conflict. All but the smallest group is almost certain to have every skill they might need from a too small pool of possible choices & the smallest groups should be given a rule of their own rather than overly condensing the entire skill system for all groups. To answer the question though, it depends on what is done with the skill system & DC ladder. If the skill system is reinflated to something like the old 50+skill array
then it wouldn't matter as much if the current rule remained but the DC ladder still keeps it problematic even with expertise to split experts from dabblers. With2-6 prof bonus & proficient skills getting 5+prof+d20 expertise is simply too much for a system still wed to bounded accuracy with "very easy" dc5 to "impossible" dc30 to have anyone
getting 5+prof+prof+d20 on one or more skills unless the GM is given back something like the old DC-10 to DCforty three DC ladder
to accommodate PC's getting d20+13 d20+15 or d20+17. If something like both of those changes are made it might not matter if players are given a choice between wide & shallow or narrow & skilled as long as choosing the expertise consumes
the second choice so bob could pick A &C from class & expertise in C+mere proficient in Q or α while Alice might choose A&B+Σ & α.
*F tier skills, linked to dumpstat, clash with build, whatever
α that's an "alpha" symbol
Σ That's a "sigma" symbol