> makes it more convenient to through traffic
Yes, and this is a bad thing. The point of streets is to disincentivize through traffic, so that people can actually enjoy being outside in their neighbourhoods without worrying about getting hit by a motorist.
Well-designed cities don't rely on 18-wheelers being able to pass through their suburbs. In fact, they design to prevent that. Instead, an arterial road network allows overland shipping traffic to arrive and terminate at industrial hubs and big-box stores within cities; whereupon cargo is then transshipped onto "street-sized" delivery vehicles for last-mile delivery to homes and retail shops.
Logistics architectures designed before the advent of stroads still work this way, even in stroaded cities. For example, USPS: big trucks between hubs; little slow-moving trucks for the last mile.
> a bit of compromise to ease of crossing
Perhaps "a bit" if you're imagining the goal of a pedestrian is to commute. It's not too bad to cross a stroad once a day to get to and from a train station, sure.
But many of the worst stroads, exist in place of streets in what could and should be outdoor shopping malls, transforming them instead into strip malls. "A bunch of businesses on either side of a busy road" does not invite browsing. If the goal of the businesses in that area was to congregate together to achieve the sort of back-and-forth "let's go to X while we're here" foot traffic that a popular mall receives, then the "elevation" of a street into a stroad basically ruins the whole premise.
And, of course, there's the stroads in residential areas, where in cities where these were laid out as streets, children would literally be allowed to play in the street — not crossing, but using the street itself as a place to be present in — because traffic was going at a reasonable speed to react in time to stop if they saw children playing. Today, that safe speed is reserved for "school zones." Why should the area around a school be safer for children to be present in than the area immediately outside your home?
> not even particularly much detriment to walking on a single side.
...if you trust drivers. Stroads put sidewalks in the middle of what, on a road, would be the ditch area for cars to roll to a stop on when they're out of control. On a stroad, the cars aren't going much slower (for a few minutes, between stoplights), so cars still need that ditch area. But on a stroad, that ditch area has people walking in it. Bad idea, no?
...and if there aren't features like overpasses as part of the stroad, where all pretense of pedestrian access — especially accessible pedestrian access — is usually forgotten.
...and if it's doesn't snow where you live. Stroad sidewalks are rarely de-iced the way the stroads themselves are. In fact they're often iced — snowblowers taking ice and snow and blowing it off the stroad and onto its vestigial sidewalks.
(And don't get me started on non-separated stroad "bike lanes." Often sharing the same space as parking cars, cars turning into cross-streets, or worst, the suddenly open doors of parked cars.)