dont worry about quantum so much
(note i am purposefully translating quantum logic into very dumbed down human understanding scenario just for demo purpose)

the binary algo has to follow binary rules. and as such quantum would need to show an input and a result that is acceptable to a binary system

imagine it like a sat nav
imagine one sat nav can only direct traffic in 2 directions (forward(0) and right(1))
01001001

> >> v
^       v
         v
         <

if quantum(4logic gates) had 0forward 1right 2 left 3back
it could get to destination in
33200
11020
and many other paths.. but here is the thing..binary will not understand all of these lefts2 and backs3 and wont accept it

so quantum would then need to translate the 2's and 3's into results that result in the same destination but only using 0's and 1's which is an extra task

so quantum cant use all of its capability to find all possible routes in its quantum state. it has to instead use the route method of binary where by it potentially can try multiple binary paths at once.
which is just a efficiency of 2x factor (using 4gate to perform 2 functions of binary(2gate) logic)

EG
instead of
01001001 it can get to destination in
100101 (this fails because algo would add 00 to the end to get the required acceptable bitlength, thus alters the route)
1010 (this fails because algo would add 0000 to the end to get the required acceptable bitlength, thus alters the route)

where the only other option it might find that fits the rule may be instead of
01001001  it finds 10001010

> > > v
^        v                > > > > v
          v                             v
         <                         < <

so its not so simple for quantum to just brute binary as you may think