There are certain motor racing categories where things like engines (or even entire cars) are provided by the race organiser and teams are not allowed to make any modifications. Formula A1 comes to mind as an example.
These categories are much more focussed on the driver, as the racetrack and cars are all identical.
I'm pretty sure that something like this can be brought into cycle racing. Everybody gets the same frame, wheelset, crankset and groupset, and you install your own cockpit (saddle and handlebars).
F1 Cars are completely custom built by the team, and even different drivers within the same team drive essentially different cars. The suspension setup, handling profile, seat, steering wheel and button layout are all custom done for the driver.
These categories are much more focussed on the driver, as the racetrack and cars are all identical.
I'm pretty sure that something like this can be brought into cycle racing. Everybody gets the same frame, wheelset, crankset and groupset, and you install your own cockpit (saddle and handlebars).