Can’t report any practical experience on either of those items, lol. Just some trends I’ve seen over the last couple of years that I thought might add to the debate
I used to have a very long commute (60km one way) that I did in full lycra and with only my work swipe card as extra luggage. Now I have a very short (4km) commute that I just do in my work gear (jeans and tshirt, luckily) with a normal backpack.
I’ve been happy with Du/er pants for being both comfortable for riding and office appropriate. Less of a hassle than changing at the office (or the theater or whatever other location I’m riding to). They’re not cheap, though (though I haven’t price checked with traditional office pants or jeans lately, either).
If I was carrying a laptop I’d use my pannier dry bag (ortlieb). I don’t like riding with stuff on my back if I can help it and it rains too much here to not use a dry bag for a laptop.
Yip it falls down in the city. Like I was saying, I am lucky enough to have a commute that’s mostly rural (apart from the rat running drivers) and when it goes quiet it helps me chill 
It was a few years pre-pandemic since I regularly bike commuted, but as others have said the big change I notice is the number of ebikes and scooters. I park and cycle my commute, and I’m quite tempted by a rear hub motor tbh - thinking of human power in from further out, and then motor on for home in the evening (predominantly false flat uphill into the prevailing wind). I’ve seen quite a few posts saying that lots start with this intention, but the weight and drag means it doesn’t happen. I do find the evening spin/ double day takes more out of me than a spin of the same total distance.
Someone mentioned Dyno hubs earlier - definitely the best addition I’ve made. I brought a full wheel from bikediscount, and a B&M German standard 100 lumen light. Adds a bit of weight and drag, but throws out great light in an appropriate patten, and never a worry about batteries/ charging lights.
Hahaha !! Yes, I suppose I should have phrased that differently… especially as I make a point of stopping at red lights and ostentatiously trackstanding 
Ortlieb do some good laptop cases that look smart and clip onto a pannier. I’ve got one and would definitely recommend it.
I think a big change over recent years is its got harder to buy shoes with cleats suitable for both the commute and the office which I find really frustrating 
but these just dropped Chelsea Cycling Boot - Brown | QUOC 