This will probably make some people angry - how about putting the three letter surname identifiers somewhere clear on the car, rather than making the numbers bigger? Easier to identify for everyone, experienced or new fans.
You mean like this?

It was allowed in 2017 when the rules were clarified. But it appears that has been taken out of the rules.
https://www.fia.com/..._2025-02-26.pdf
9) CAR LIVERY AND COMPETITION NUMBERS
9.1 Car Livery
a) The provisions of the Code relating to national colours shall not apply to the Championship.
b) Both cars entered by a Competitor must be presented in substantially the same livery at every Competition, any significant change to this livery during a Championship may only be made with the agreement of the FIA and the Commercial Rights Holder.
c) In order that the cars of each Competitor may be easily distinguished from one another whilst they are on the track, the on-board cameras located above the principal roll structure of the first car must remain as it is supplied to the Competitor and the second car must be predominantly fluorescent yellow.
d) The name or the emblem of the make of the car must appear on the front of the nose of the car and in either case be at least 25mm in its largest dimension.
e) The name of the driver must appear on the external bodywork of the car and be clearly legible.
f) Each car will carry the competition number of its driver as published by the FIA at the beginning of the Championship or the competition number that has been allocated to his replacement in accordance with Article 32.4c). This number must be clearly visible from the front of the car and on the driver’s crash helmet.
9.2 Competition Numbers
a) Prior to the start of the 2014 FIA Formula One World Championship competition numbers were permanently allocated to drivers by ballot, such numbers must then be used by that driver during every Formula One World Championship Competition he takes part in throughout his career in Formula 1.
b) A driver’s career in Formula 1 will be deemed to have ended if he does not participate in a Competition for two (2) entire consecutive Championships.
c) Any new drivers, either at the start of or during a Championship, will also be allocated a permanent competition number in the same way.
d) The only exception to this allocation process will be for the reigning World Champion who will have the option to use the number one. The competition number that was previously allocated to him will be reserved for him in subsequent Championship if he does not retain the title of World Champion.
I don't see why they can't have more specific rules about the numbers, exactly as they do for the car emblem in 9.1 d.