Yes, but it's not practical at this point. And there were more important steps to be taken anyway.
The so-called Standard Gauge became standard in part because railways that used that gauge lobbied Parliament in Britain to do it, rather than adapt the clearly superior broad gauge of the Great Western Railway of Brunel -- which had tracks 7 feet 1/4 inches wide.
Do the math, it's more than 2 feet 3 inches wider. It allows for great freight loads, more stability and ultimately higher speeds. But modern development has taken away most of the speed advantages, especially on passenger lines. There is somewhat less concern about top heaviness in wide gauge, but that currently is not a major concern.
The costs are considerably higher, i.e. roadbeds need to be wider and of the some level of work if the benefits are to be achieved. Cuts and tunnels must be wider.
There are some rail systems that mix wider gauges with narrower gauges, but it's somewhat difficult, especially when passenger trains and multiple trackways are involved. In the late 1880s, the United States converted all of its major railways, about 30,000 miles, in a single day to standard guage.
The French considered a wider gauge for the TGV lines, but it would have entailed too great an expense for what are essentially lightweight (only in some ways) trains. They took the steps of using a standard gauge with wider separation between each set of tracks (to reduce wind buffting, etc) and less sharp curves etc.
Because they are standard gauge, however, they can be run into areas with high speed rail tracks, i.e. LGV are TGV tracks, but they run at lower speeds. This allowed expansion of the network much faster. It may no longer be true, but the Paris-Dijon line was an example. Some TGVS ran high speed to a junction off to Dijon and then ran at slower speeds. The mainline continued on at full speed to Lyons and beyond. The trains are designed to run on multiple voltages as ell, although the 130k voltes overhead is preferred.
The caution here is that a bad wide gauge line is not as good as a well maintained standard gauage. And a couple of inches won't make much difference. The Spanish still run wide guage, but most of their new high speed lines are standard gauge which allows them to run on the same tracks as the rest of the European network. The Russian guage was wide gauge in part to slow invasions. Narrower than standard gauge was used both to reflect projected loads and to lower construction coasts.
The primary older Japanese system was narrower than standard guage, but the bullet trains are regular width.
Converting now would require substantial expense just to get where we are and wide rails would not connect to existing tracks. Modern standard gauge rail has been vastly improved in technology which has caused most redeveloped lines to be put into that gauge.
The biggest improvements in railroads vary according to whether they are freight or rail. Freight lines in the U.S. need to be modified so that they can carry double stack container trains and the heaviest loads. Bottlenecks would need to be removed that force many miles of detours, tunnels widened and made higher. The problem is especially acute in the Northeast and in some older cities where rail dates to the 1800s in basic routing or structure. Trackbed improvements can only go so far. It ramins the most cost effective means of moving heavy freight, but lacks some of the flexibility of other methods -- for now.
In passenger traffic, almost everything in the United States is underfunded and too old. Trackage needs to be straightened and sometimes routes changed to make them somewhat more direct. Passenger only lines need roadbed improvement and in a sense, rail can't improve until there is more of it.
In areas where there is considerable rail service, e.g. the NYC area, more lines need to be electrified and (with the exception of subway service) should be given modernized catenary overhead.
At this point, our rail system is so deficient that wide gauge just isn't an issue and likely never will be. Had w started that way and kept it, it would be the only thing that made sense.
Hitler at one time fantanszied about building a superwide guage railroad from the German ports to the interior to supplement regular rail. But it was never really planned.
There may be conditions under which it would make sense to build wide gauge to perform specific heavy load functions in the same way we building supersized trucks for pit mining. But these would be point to point lines over routes that have exceeded their tonnage limits and that would meet specific condition.