splitpath certainly still exists (the output below is for Julia 1.10.4):
julia> splitpath
splitpath (generic function with 2 methods)
help?> splitpath
search: splitpath
splitpath(path::AbstractString) -> Vector{String}
Split a file path into all its path components. This is the opposite of joinpath. Returns an array of substrings,
one for each directory or file in the path, including the root directory if present.
│ Julia 1.1
│
│ This function requires at least Julia 1.1.
Examples
≡≡≡≡≡≡≡≡
julia> splitpath("/home/myuser/example.jl")
4-element Vector{String}:
"/"
"home"
"myuser"
"example.jl"
The list you get from help?> path simply is not exhaustive.