In my opinion, declining dress standards in the City have much to do with the demise of the suit. We all agree a smart suit is what a man should be wearing to work if he's in a position of responsibility, so I'm not sure why they don't.
Perhaps it's the difficulty of keeping a suit looking crisp, and if that's what it is, take a leaf out of my book.
I have two suits (both navy blue) which I bought six months ago when I was promoted, and for each one, I bought the jacket plus two pairs of trousers. So in total I've got two jackets and four pairs of trousers.
The logic is that the trousers in a suit get more wear and tear than the jacket, because you often wear the trousers but not the jacket. Most times, you have the jacket on the back of your chair and on warm days you don't wear the jacket at all. You may start the day in a suit, but there's an awful lot of time when you're wearing the trousers without the jacket.
(It would balance out if the same thing were true the other way around, but it isn't because you're hardly ever going to be wearing the jacket without the trousers. In fact, I can't actually think of a single occasion where you'd do that. So strictly speaking, based on relative wear and tear, something like three or four pairs of trousers for each jacket might even make more sense.)
Given the above, I have an excellent system worked out with my suits.
I rotate the jackets - I wear one on Monday, the other on Tuesday, back to the first one on Wednesday and so on. And then within that rotation I also rotate the trousers. I can do that because both my suits are exactly the same shade of navy blue.
It's not as complicated as it sounds.
Say suit1 is made up of jacket J1 + trousers T1a and T1b, and suit2 is jacket J2 and trousers T2a and T2b, so it goes like this:
On day 1, I wear J1 + T1a
On day 2, I wear J2 + T1b
On day 3, I wear J1 + T2a
On day 4, I wear J2 + T2b
On day 5, I wear J1 + T1b
On day 6, I wear J2 + T1a
On day 7, I wear J1 + T2b
On day 8, I wear J2 + T2a
See how I effectively end up wearing a different suit every day for eight days?
And since we have a 'Casual Friday' policy at work, it may look like I'm wearing exactly the same suit the whole time, but I'm actually wearing the same exact combination only once a fortnight!