In his book "The Englishman's suit", Hardy Amies gives a clear account of the development of formal wear, as a natural progression of standards slipping downwards, though he ingeniously frames this as styles climbing upwards. At any point in time fairly recently (i.e. over the half millenia or so), there
has been court wear, evening wear, day wear, and sports wear. A generation or two later, the court wear has vanished; the evening wear is the new court wear; the day wear is the new evening wear; and the sports wear is the new day wear. New sports wear has been invented.
This process seems to have slowed a little over the past century or so. I suppose this is because daywrae of 50 years ago has become kind of stuck; sports wear in the form of track suits has not managed to bump itself up into the daywear category (I mean it has for the lower orders but not for example in professional's offices, or lounging in country estates (well not that kind of estate)). (Amies mentions trying and failing to get anywhere with an evening tracksuit)
Proposed is to take serious sportswear of the present day, by which I suppose I mean not track suits or football strip, but mountaineering gear. Mountaineers are very serious about their wardrobes, with layers and functions and ensuring items match in a functional way for specific purposes.
I submit that serious technical clothing manufacturers produce "formal" lines, which are constructed and tailored in exactly the same way as their norrmal garments, but in sombre charcoal grey shades and with the logos and brand labelling either entirely absent or banished to the inside.
If the garments were fitted by one's tailor as usual, and built from carefully selected fabrics and colours, they should be able to fit into any daywear scenario without raising an eyebrow, except for connoiseurs who would be delighted about the care and attention to detail displayed.
This could legitimately allow the lounge suit to become the norm for evening wear, banishing the dinner-jacket to court and allowing the morning coat and tail-coat to expire gracefully in the natural order of things.
*The category is not ideal, since the idea is for formal wear not for actualsports wear. However, it was not possible to put the idea into Fashion: Suit, since gentlemans' formal wear is by definition not "fashion".