Einspurer-VMs - gibt es die noch?
Yes clearly there are a few but you see them rarely/never on the road, only in circuit races.
On the racing track, the speed difference between streamliners and velomobiles seems to have leveled out in the last years. When well tuned, both seem to run about 70 km/h at 250W. Only in tight turns and good weather, streamliners seem to have the edge over velomobiles.
In daily traffic (so not on a racing circuit), raw top speed is also much less relevant. You need to break very frequently for sharp turns, traffic lights obscure situations and intersections, objects and turns in the road obstructing the view on the traffic, other traffic, narrow bike lanes, bad road conditions, gusts of wind etc. Often these are so frequent that you can not even reach cruising speed before the next breaking point. On a standard narrow two-directional bike path some 40-45 km/h seems already be a stretch. Driving on the main road often is not legal, and if it is, a big speed difference with the cars often makes it unsafe to use. And these frequent stopping/breaking points have a huge impact on your total travel time.
I think the main step towards faster and safer travel by bike would require a drastically improved infrastructure.
What we need to cycle quickly (with high AVERAGE speed) is the bike equivalent of a highway: a country-level network with lanes for the two directions completely separated; entry and exit lanes; no crossings with other roads on the same level; no traffic lights or points where you need to stop, more equal speeds on the various lanes, etc. The bike highway will give a similar improvement to biking as car highways do.
Therefore speed is less of a concern (you are close to max anyway) and for daily travel other factors like comfort become more important.